Communication apparatus and communication method

ABSTRACT

Provided is a communication apparatus that includes a control unit that performs control such that a plurality of reference signals associated with pieces of antenna information different from each other is transmitted to a terminal apparatus, and an acquisition unit that acquires control information corresponding to at least any one of the plurality of reference signals from the terminal apparatus after a random access response in a random access procedure is transmitted to the terminal apparatus. The control unit controls following communication with the terminal apparatus on the basis of the antenna information corresponding to the acquired control information.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/643,915 filed on Dec. 13, 2021 which is continuation of Ser. No.16/620,041 filed Dec. 6, 2019, now U.S. Pat. No. 11,240,851, which is aU.S. National Phase of International Patent Application No.PCT/JP2018/018081 filed May 10, 2018, which claims priority benefit ofJapanese Patent Application No. JP 2017-117977 filed in the Japan PatentOffice on Jun. 15, 2017. Each of the above-referenced applications ishereby incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to a communication apparatus, acommunication method, and a program.

BACKGROUND ART

Wireless access methods and wireless networks of cellular mobilecommunication (hereinafter also referred to as “Long Term Evolution(LTE),” “LTE-Advanced (LTE-A),” “LTE-Advanced Pro (LTE-A pro),” “NewRadio (NR),” “New Radio Access Technology (NRAT),” “Evolved UniversalTerrestrial Radio Access (EUTRA),” or “Further EUTRA (FEUTRA)”) havebeen studied in 3rd generation partnership project (3GPP). Note that LTEincludes LTE-A, TTE-A pro, and EUTRA, and that NR includes NRAT andFEUTRA in the following description. A base station apparatus (basestation) in LTE is also referred to as eNodeB (evolved NodeB). A basestation apparatus (base station) in NR is also referred to as gNodeB. Aterminal apparatus (mobile station, mobile station apparatus, orterminal) in each of LTE and NR is also referred to as UE (UserEquipment). Each of LTE and NR is a cellular communication system wherea plurality of areas covered by a base station apparatus is arranged ina form of cells. The single base station apparatus may manage aplurality of cells.

NR as a next-generation wireless access system for LTE is RAT (RadioAccess Technology) different from LTE. NR is an access technologycapable of coping with various use cases including eMBB (Enhanced mobilebroadband), mMTC (Massive machine type communications), and URLLC (Ultrareliable and low latency communications). NR has been studied with anaim of providing a technical framework coping with a use scenario, arequirement condition, an arrangement scenario and the like in each ofthese use cases of NR.

NR performs beamforming for purposes of coverage extension, high-qualitycommunication and the like. A high-quality link can be provided byaligning directions of transmission and reception beams of a basestation apparatus and a terminal apparatus in an appropriate direction.The appropriate beam varies in accordance with a shift of the terminalapparatus and a change of channel quality. Accordingly, beam managementis performed between the base station apparatus and the terminalapparatus on each occasion. Details of the beam management are disclosedin NPL 1, for example.

CITATION LIST Non Patent Literature

[NPL 1]

-   Huawei, HiSilicon, “Beam Management Procedure for NR MIMO,”    R1-166089, 3GPP TSG RAN WG1 Meeting #86, Gothenburg, Sweden, August,    2016.

SUMMARY Technical Problem

Meanwhile, in a situation where the foregoing beam management isperformed, it is an important object to provide a wireless link usablein a stable manner. Particularly during a random access procedure, theprocedure is difficult to complete in a case where an unstable wirelesslink is provided between the base station apparatus and the terminalapparatus. In this case, a start of communication may become difficult.

Accordingly, the present disclosure proposes a communication apparatus,a communication method, and a program capable of providing a wirelesslink usable in a more stable manner in a situation where beam managementis performed.

Solution to Problem

Provided according to the present disclosure is a communicationapparatus including: a control unit that performs control such that aplurality of reference signals associated with pieces of antennainformation different from each other is transmitted to a terminalapparatus; and an acquisition unit that acquires control informationcorresponding to at least any one of the plurality of reference signalsfrom the terminal apparatus after a random access response in a randomaccess procedure is transmitted to the terminal apparatus. The controlunit controls following communication with the terminal apparatus on thebasis of the antenna information corresponding to the acquired controlinformation.

In addition, provided according to the present disclosure is acommunication apparatus including: a selection unit that selects atleast a part of a plurality of reference signals transmitted from a basestation and associated with pieces of antenna information different fromeach other, the part of the plurality of reference signals beingselected in accordance with a reception result of the reference signals;and a notice unit that gives a notice of control informationcorresponding to the selected reference signal to the base station afterreception of a random access response transmitted from the base stationin a random access procedure.

In addition, provided according to the present disclosure is acommunication method performed by a computer, the method including:performing control such that a plurality of reference signals associatedwith pieces of antenna information different from each other istransmitted to a terminal apparatus; acquiring control informationcorresponding to at least any one of the plurality of reference signalsfrom the terminal apparatus after a random access response in a randomaccess procedure is transmitted to the terminal apparatus; andcontrolling following communication with the terminal apparatus on thebasis of the antenna information corresponding to the acquired controlinformation.

In addition, provided according to the present disclosure is acommunication method performed by a computer, the method including:selecting at least a part of a plurality of reference signalstransmitted from a base station and associated with pieces of antennainformation different from each other, the part of the plurality ofreference signals being selected in accordance with a reception resultof the reference signals; and giving a notice of control informationcorresponding to the selected reference signal to the base station afterreception of a random access response transmitted from the base stationin a random access procedure.

In addition, provided according to the present disclosure is a programunder which a computer executes: performing control such that aplurality of reference signals associated with pieces of antennainformation different from each other is transmitted to a terminalapparatus; acquiring control information corresponding to at least anyone of the plurality of reference signals from the terminal apparatusafter a random access response in a random access procedure istransmitted to the terminal apparatus; and controlling followingcommunication with the terminal apparatus on the basis of the antennainformation corresponding to the acquired control information.

In addition, provided according to the present disclosure is a programunder which a computer executes: selecting at least a part of aplurality of reference signals transmitted from a base station andassociated with pieces of antenna information different from each other,the part of the plurality of reference signals being selected inaccordance with a reception result of the reference signals; and givinga notice of control information corresponding to the selected referencesignal to the base station after reception of a random access responsetransmitted from the base station in a random access procedure.

Advantageous Effect of Invention

As described above, provided according to the present disclosure are acommunication apparatus, a communication method, and a program capableof providing a wireless link usable in a more stable manner in asituation where beam management is performed.

Note that advantageous effects to be produced are not limited to theadvantageous effect described above. Any advantageous effects presentedin the present description, or other advantageous effects conceivablefrom the present description may be produced in addition to or in placedof the advantageous effect described above.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram depicting an example of setting of a componentcarrier according to an embodiment of the present disclosure.

FIG. 2 is a diagram depicting an example of setting of the componentcarrier according to the embodiment.

FIG. 3 is a diagram depicting an example of a downlink sub frame of NRaccording to the embodiment.

FIG. 4 is a diagram depicting an example of an uplink sub frame of NRaccording to the embodiment.

FIG. 5 is a schematic block diagram depicting a configuration of a basestation apparatus of the embodiment.

FIG. 6 is a schematic block diagram depicting a configuration of aterminal apparatus 2 of the embodiment.

FIGS. 7A, 7B, and 7C are diagrams depicting an example of a frameconfiguration of self-contained transmission according to theembodiment.

FIG. 8 is a schematic block diagram depicting an example of a digitalantenna configuration according to the present embodiment.

FIG. 9 is a schematic block diagram depicting another example of thedigital antenna configuration according to the present embodiment.

FIG. 10 is an explanatory diagram for explaining an outline of anexample of a single beam operation.

FIG. 11 is an explanatory diagram for explaining an outline of anexample of a plural beam operation.

FIG. 12 is a diagram depicting an example of an initial connectionprocedure of the terminal apparatus.

FIG. 13 is a diagram depicting an example of a configuration of asynchronization signal block.

FIG. 14 is a diagram depicting an example of configurations asynchronization signal burst and a synchronization signal burst set.

FIG. 15 is a diagram depicting an example of system informationcorresponding to synchronization signal blocks.

FIG. 16 is a diagram depicting an example of a sequence of systeminformation corresponding to synchronization signal blocks.

FIG. 17 is a diagram depicting an example of a correspondence tableindicating correspondence between a time index and a CRC mask.

FIG. 18 is a diagram depicting an example of a communication sequence ofinitial beam selection in NR.

FIG. 19 is a diagram depicting an example of types of beam in beamrefinement.

FIG. 20 is a diagram depicting an example of a communication sequence inbeam management according to the embodiment.

FIG. 21 is a diagram depicting an example of a communication sequence inbeam management according to the embodiment.

FIG. 22 is a block diagram depicting a first example of a schematicconfiguration of eNB.

FIG. 23 is a block diagram depicting a second example of the schematicconfiguration of eNB.

FIG. 24 is a block diagram depicting an example of a schematicconfiguration of a smartphone.

FIG. 25 is a block diagram depicting an example of a schematicconfiguration of a car navigation apparatus.

DESCRIPTION OF EMBODIMENT

A preferred embodiment according to the present disclosure will behereinafter described in detail with reference to the accompanyingdrawings. Note that components having substantially identical functionalconfigurations in the present specification and the drawings are givenidentical reference numbers, and therefore are not repeatedly described.

Note that the description will be presented in a following order.

-   -   1. Embodiment    -   2. Application Examples    -   2.1. Application Example of Base Station    -   2.2. Application Example of Terminal Apparatus    -   3. Conclusion

1. Embodiment

A preferred embodiment according to the present disclosure will behereinafter described in detail with reference to the accompanyingdrawings. Note that components having substantially identical functionalconfigurations in the present specification and the drawings are givenidentical reference numbers, and therefore are not repeatedly described.In addition, all items of the description, such as technologies,functions, methods, configurations, and procedures described hereinafterare applicable to LTE and NR unless otherwise stated.

<Wireless Communication System in Present Embodiment>

A wireless communication system in the present embodiment includes atleast a base station apparatus 1 and a terminal apparatus 2. The basestation apparatus 1 is capable of containing a plurality of terminalapparatuses. The base station apparatus 1 is connectable to other basestation apparatuses by means of an X2 interface. In addition, the basestation apparatus 1 is connectable to EPC (Evolved Packed Core) by meansof an S1 interface. Moreover, the base station apparatus 1 isconnectable to MME (Mobility Management Entity) by means of an S1-MMEinterface, and is connectable to S-GW (Serving Gateway) by means of anS1-U interface. The S1 interface supports many-to-many connectionbetween MME and/or S-GW and the base station apparatus 1. Furthermore,each of the base station apparatus 1 and the terminal apparatus 2 in thepresent embodiment supports LTE and/or NR.

<Wireless Access Technology in Present Embodiment>

Each of the base station apparatus 1 and the terminal apparatus 2 in thepresent embodiment supports one or more wireless access technologies(RATs). For example, The RATs include LTE and NR. The one RATcorresponds to one cell (component carrier). More specifically, in acase where a plural RATs are supported, these RATs are associated withcorresponding cells different from each other. Each cell in the presentembodiment is constituted by a combination of a downlink resource, anuplink resource, and/or a side link. In addition, in the followingdescription, a cell corresponding to LTE is referred to as an LTE cell,while a cell corresponding to NR is referred to as NR cell.

Downlink communication is communication from the base station apparatus1 to the terminal apparatus 2. Downlink transmission is transmissionfrom the base station apparatus 1 to the terminal apparatus 2, andtransmission of a downlink physical channel and/or a downlink physicalsignal. Uplink communication is communication from the terminalapparatus 2 to the base station apparatus 1. Uplink transmission istransmission from the terminal apparatus 2 to the base station apparatus1, and transmission of an uplink physical channel and/or an uplinkphysical signal. Side link communication is communication from theterminal apparatus 2 to another terminal apparatus 2. Side linktransmission is transmission from the terminal apparatus 2 to anotherterminal apparatus 2, and transmission of a side link physical channeland/or a side link physical signal.

The side link communication is defined for near and direct detection andnear and direct communication between the terminal apparatuses. The sidelink communication may have a frame configuration similar to that of theuplink and the downlink. In addition, the side link communication may belimited to a part (sub-set) of the uplink resource and/or the downlinkresource.

Each of the base station apparatus 1 and the terminal apparatus 2 iscapable of supporting communication which uses an aggregation of one ormore cells in each of the downlink, the uplink, and/or the side link. Anaggregation of a plurality of cells or communication using anaggregation of a plurality of cells is also referred to as a carrieraggregation or dual connectivity. Details of the carrier aggregation andthe dual connectivity will be described below. In addition, each celluses a predetermined frequency bandwidth. A maximum value, a minimumvalue, and settable values in the predetermined frequency bandwidth maybe specified in advance.

FIG. 1 is a diagram depicting an example of setting of a componentcarrier according to the present embodiment. In the example of FIG. 1 ,one LTE cell and two NR cells are set. The one LTE cell is set as aprimary cell. The two NR cells are set as a primary secondary cell and asecondary cell, respectively. The two NR cells are converged by carrieraggregation. In addition, the LTE cell and the NR cell are converged bydual connectivity. Note that the LTE cell and the NR cell may beconverged by carrier aggregation. In the example of FIG. 1 , connectionof NR can be assisted by the LTE cell as the primary cell. Accordingly,a part of functions such as a function for achieving stand-alonecommunication need not be supported. The function for achievingstand-alone communication includes a function necessary for initialconnection.

FIG. 2 is a diagram depicting an example of setting of the componentcarrier according to the present embodiment. In the example of FIG. 2 ,two NR cells are set. The two NR cells are set as a primary cell and asecondary cell, respectively, and converged by carrier aggregation. Inthis case, the NR cell supports the function for achieving stand-alonecommunication, wherefore assistance by the LTE cell is unnecessary. Notethat the two NR cells may be converged by dual connectivity.

<Wireless Frame Configuration in Present Embodiment>

In the present embodiment, wireless frames (radio frames) each having 10ms (milliseconds) are specified. Each of the wireless frames includestwo half frames. —Each of the half frames has a time interval of 5 ms.Each of the half frames includes five sub frames. Each of the sub frameshas a time interval of 1 ms, and is defined by two successive slots.Each of the slots has a time interval of 0.5 ms. An ith sub frame in thewireless frame includes a (2×i)th slot and a (2×i+1)th slot.Accordingly, 10 sub frames are specified in each of the wireless frames.

<Frame Configuration of NR in Present Embodiment>

One or more predetermined parameters are used in a predetermined timelength (e.g., sub frame) in each of NR cells. More specifically, each ofa downlink signal and an uplink signal in the NR cell is generated usingone or more predetermined parameters in the predetermined time length.In other words, the terminal apparatus 2 assumes that each of a downlinksignal transmitted from the base station apparatus 1, and an uplinksignal transmitted to the base station apparatus 1 is generated usingone or more predetermined parameters in the predetermined time length.In addition, the base station apparatus 1 can establish settings suchthat each of a downlink signal transmitted to the terminal apparatus 2,and an uplink signal transmitted from the terminal apparatus 2 isgenerated using one or more predetermined parameters in thepredetermined time length. In a case where a plurality of predeterminedparameters is used, signals generated using these predeterminedparameters are multiplexed by a predetermined method. Examples of thepredetermined method include FDM (Frequency Division Multiplexing), TDM(Time Division Multiplexing), CDM (Code Division Multiplexing), and/orSDM (Spatial Division Multiplexing).

FIG. 3 is a diagram depicting an example of the downlink sub frame of NRin the present embodiment. In the example of FIG. 3 , signals eachgenerated using a parameter set 1, a parameter set 0, and a parameterset 2 are multiplexed by FDM in a cell (system bandwidth). The diagramdepicted in FIG. 3 is also referred to as a downlink resource grid ofNR. The base station apparatus 1 is capable of transmitting a downlinkphysical channel of NR and/or a downlink physical signal of NR in adownlink sub frame to the terminal apparatus 2. The terminal apparatus 2is capable of receiving a downlink physical channel of NR and/or adownlink physical signal of NR in a downlink sub frame from the basestation apparatus 1.

FIG. 4 is a diagram depicting an example of an uplink sub frame of NR inthe present embodiment. In the example of FIG. 4 , signals eachgenerated using the parameter set 1, the parameter set 0, and theparameter set 2 are multiplexed by FDM in a cell (system bandwidth). Thediagram depicted in FIG. 3 is also referred to as an uplink resourcegrid of NR. The base station apparatus 1 is capable of transmitting anuplink physical channel of NR and/or an uplink physical signal of NR inan uplink sub frame to the terminal apparatus 2. The terminal apparatus2 is capable of receiving an uplink physical channel of NR and/or anuplink physical signal of NR in an uplink sub frame from the basestation apparatus 1.

For example, a physical resource may be defined in a following manner inthe present embodiment. One slot is defined by a plurality of symbols. Aphysical signal or a physical channel transmitted in each slot isrepresented by a resource grid. A resource grid in a downlink may bedefined by a plurality of sub carriers in a frequency direction, and aplurality of OFDM symbols in a time direction. In addition, a resourcegrid in an uplink may be defined by a plurality of sub carriers in thefrequency direction, and a plurality of OFDM symbols or SC-FDMA symbolsin the time direction. The number of the sub carriers or resource blocksmay be determined in accordance with the bandwidth of the cell. Forexample, the number of symbols in one slot may be determined inaccordance with the type of CP (Cyclic Prefix). Examples of the types ofCP include a normal CP and an extension CP. In the normal CP, the numberof OFDM symbols or SC-FDMA symbols constituting one slot is 7. In theextension CP, the number of OFDM symbols or SC-FDMA symbols constitutingone slot is 6. Each of elements within the resource grid is referred toas a resource element. Each of the resource elements is identified byusing an index (number) of the sub carrier and an index (number) of thesymbol. Note that the OFDM symbol or the SC-FDMA symbol is also simplyreferred to as a symbol in the description of the present embodiment.

A resource block is used for mapping a certain physical channel (e.g.,PDSCH or PUSCH) to a resource element. The resource block may include avirtual resource block and a physical resource block, for example. Acertain physical channel is mapped to the virtual resource block. Thevirtual resource block is mapped to the physical resource block. Onephysical resource block is defined by a predetermined number ofsuccessive symbols in a time range, for example. In addition, onephysical resource block is defined by a predetermined number ofsuccessive sub carriers in a frequency range, for example. The number ofsymbols and the number of sub carriers in one physical resource blockare determined on the basis of parameters or the like set in accordancewith the type of CP, a sub carrier interval, and/or an upper layer inthe corresponding cell. For example, in a case where the type of CP is anormal CP with the sub carrier interval of 15 kHz, the number of symbolsand the number of sub carriers are 7 and 12, respectively, in onephysical resource block. In this case, therefore, each of the physicalresource blocks includes (7×12) resource elements. The physical resourceblocks are given numbers starting from 0 in the frequency range. Inaddition, two resource blocks within one sub frame, with each of whichan identical physical resource block number is associated, are definedas a physical resource block pair (PRB pair, RB pair).

<Antenna Port in Present Embodiment>

An antenna port is defined to estimate a propagation channel carrying acertain symbol from a propagation channel carrying another symbol in anidentical antenna port. For example, it is assumable that differentphysical resources in an identical antenna port are transmitted by anidentical propagation channel. In other words, a symbol in a certainantenna port can be demodulated by estimating a propagation channel onthe basis of a reference signal in the corresponding antenna port. Inaddition, one resource grid is present for each antenna port. Eachantenna port is defined by a reference signal. Furthermore, eachreference signal can define a plurality of antenna ports.

Respective antenna ports are specified or identified by antenna portnumbers. For example, antenna ports 0 to 3 are antenna ports throughwhich CRS is transmitted. Accordingly, a PDSCH transmitted through theantenna ports 0 to 3 is demodulated by CRS corresponding to the antennaports 0 to 3.

In a case where two antenna ports meet a predetermined condition, thetwo antenna ports are allowed to be expressed as ports exhibiting quasico-location (QCL). The predetermined condition is a condition thatwide-range characteristics of a propagation channel carrying a symbol ina certain antenna port can be estimated from a propagation channelcarrying a symbol in another antenna port. The wide-rangecharacteristics include a delay dispersion, a Doppler spread, a Dopplershift, and an average gain and/or an average delay.

In the present embodiment, a different antenna port number may bedefined for each RAT, or a common antenna port number may be defined forRATs. For example, the antenna ports 0 to 3 in LTE are antenna ports inwhich CRS is transmitted. The antenna ports 0 to 3 in NR may beconsidered as antenna ports in which CRS is transmitted similarly tothose in LTE. In addition, the antenna ports in which CRS is transmittedin NR similarly to those in LTE may have antenna port numbers differentfrom the antenna ports 0 to 3. In the description of the presentembodiment, the predetermined antenna port numbers are applicable to LTEand/or NR.

<Downlink Physical Channel in Present Embodiment>

A PBCH is used to give a notification of an MIB (Master InformationBlock) which is notification information peculiar to a serving cell ofthe base station apparatus 1. An SFN is a wireless frame number (systemframe number). The MIB is system information. For example, the MIBincludes information indicating the SFN.

Each of the PDCCH and the EPDCCH is used to transmit downlink controlinformation (DCI). Mapping of information bits of the downlink controlinformation is defined as a DCI format. The downlink control informationincludes a downlink grant and an uplink grant. The downlink grant isalso referred to as downlink assignment or downlink allocation.

The PDCCH is transmitted by one or a plurality of aggregations ofsuccessive CCEs (Control Channel Elements). Each of the CCEs includesnine REGs (Resource Element Groups). Each of the REGs includes fourresource elements. In a case where the PDCCH includes the n successiveCCEs, the PDCCH starts from the CCE which meets a condition that aremainder obtained by dividing i as an index (number) of the CCE by nbecomes 0.

The EPDCCH is transmitted by one or a plurality of aggregations ofsuccessive ECCEs (Enhanced Control Channel Elements). Each of the ECCEsincludes a plurality of EREGs (Enhanced Resource Element Groups).

The downlink grant is used for scheduling of the PDSCH in a certaincell. The downlink grant is used for scheduling the PDSCH in a sub frameidentical to a sub frame in which the corresponding downlink grant istransmitted. The uplink grant is used for scheduling the PUSCH in acertain cell. The uplink grant is used for scheduling of the singlePUSCH within a sub frame four or more after a sub frame in which thecorresponding uplink grant is transmitted.

CRC (Cyclic Redundancy Check) parity bits are added to the DCI. The CRCparity bits are scrambled by an RNTI (Radio Network TemporaryIdentifier). The RNTI is an identifier capable of determiningspecification or setting in accordance with a purpose of the DCI or thelike. The RNTI is an identifier specified beforehand in specifications,an identifier set as information peculiar to a cell, an identifier setas information peculiar to the terminal apparatus 2, or an identifierset as information peculiar to a group belonging to the terminalapparatus 2. For example, the terminal apparatus 2 descrambles the CRCparity bits given to the DCI on the basis of a predetermined RNTI inmonitoring the PDCCH or the EPDCCH to identify whether the CRC iscorrect. In a case where the CRC is correct, it is recognizable that thecorresponding DCI is DCI for the terminal apparatus 2.

The PDSCH is used for transmitting downlink data (Downlink SharedChannel: DL-SCH). In addition, the PDSCH is also used for transmittingcontrol information in an upper layer.

In a PDCCH range, a plurality of PDCCHs may be multiplexed by frequency,time, and/or space multiplexing. In an EPDCCH range, a plurality ofEPDCCHs may be multiplexed by frequency, time, and/or spacemultiplexing. In a PDSCH range, a plurality of the PDSCHs may bemultiplexed by frequency, time, and/or space multiplexing. The PDCCH,the PDSCH, and/or the EPDCCH may be multiplexed by frequency, time,and/or space multiplexing.

<Downlink Physical Signal in Present Embodiment>

A synchronization signal is used for achieving synchronization of afrequency range and/or a time range of downlinks by the terminalapparatus 2. The synchronization signal includes a PSS (PrimarySynchronization Signal) and an SSS (Secondary Synchronization Signal).The synchronization signal is arranged in a predetermined sub framewithin a wireless frame. For example, the synchronization signal isarranged in each of sub frames 0, 1, 5, and 6 within a wireless frame inTDD method. The synchronization signal is arranged in each of sub frames0 and 5 within a wireless frame in FDD method.

The PSS may be used for rough frame/symbol timing synchronization(synchronization in time range), and identification of a cellidentification group. The SSS may be used for more accurate frame timingsynchronization and cell identification, and detection of a CP length.Accordingly, frame timing synchronization and cell identification areachievable by using the PSS and the SSS.

A downlink reference signal is used for performing estimation of apropagation path of a downlink physical channel, propagation pathcorrection, calculation of CSI (Channel State Information) associatedwith a downlink, and/or measurement for positioning of the terminalapparatus 2 by the terminal apparatus 2.

URS associated with the PDSCH is transmitted in a sub frame and a bandrange used for transmission of the PDSCH with which the URS isassociated. The URS is used for demodulation of the PDSCH with which theURS is associated. The URS associated with the PDSCH is transmittedthrough one or a plurality of antenna ports 5 and 7 to 14.

The PDSCH is transmitted through an antenna port used for transmissionof the CRS or the URS on the basis of a transmission mode and a DCIformat. A DCI format 1A is used for scheduling the PDSCH transmittedthrough the antenna port used for transmission of the CRS. A DCI format2D is used for scheduling the PDSCH transmitted through the antenna portused for transmission of the URS.

DMRS associated with the EPDCCH is transmitted in a sub frame and a bandrange used for transmission of the EPDCCH with which the DMRS isassociated. The DMRS is used for demodulation of the EPDCCH with whichthe DMRS is associated. The EPDCCH is transmitted through an antennaport used for transmission of the DMRS. The DMRS associated with theEPDCCH is transmitted through one or a plurality of antenna ports 107 to114.

CSI-RS is transmitted in a set sub frame. A resource for transmission ofthe CSI-RS is set by the base station apparatus 1. The CSI-RS is usedfor calculating channel state information associated with a downlink bythe terminal apparatus 2. The terminal apparatus 2 performs signalmeasurement (channel measurement) using the CSI-RS. The CSI-RS supportssetting of a part or all of antenna ports 1, 2, 4, 8, 12, 16, 24, and32. The CSI-RS is transmitted through one or a plurality of antennaports 15 to 46. Note that the antenna ports to be supported may bedetermined on the basis of a terminal apparatus capability, settings ofRRC parameters, and/or a transmission mode to be set of the terminalapparatus 2, for example.

A resource of ZP CSI-RS is set by the upper layer. The resource of theZP CSI-RS may be transmitted by power of zero output. In other words,transmission of no resource of the ZP CSI-RS is allowed. The PDSCH andthe EPDCCH are not transmitted by the set resource of the ZP CSI-RS. Forexample, the resource of the ZP CSI-RS is used for transmission of theNZP CSI-RS by a neighbor cell. In addition, for example, the resource ofthe ZP CSI-RS is used for measuring CSI-IM. In addition, for example,the resource of the ZP CSI-RS is a resource by which predeterminedchannels such as the PDSCH are not transmitted. In other words, thepredetermined channels are mapped by resources except for the resourceof the ZP CSI-RS (rate-matched, punctured).

<Uplink Physical Channel in Present Embodiment>

The PUCCH is a physical channel used for transmitting uplink controlinformation (UCI). The uplink control information includes channel stateinformation (CSI) associated with a downlink, a scheduling request (SR)indicating a request for a PUSCH resource, and HARQ-ACK for downlinkdata (Transport block: TB, Downlink-Shared Channel: DL-SCH). TheHARQ-ACK is also referred to as ACK/NACK, HARQ feedback, or responseinformation. In addition, The HARQ-ACK for downlink data indicates ACK,NACK, or DTX.

The PUSCH is a physical channel used for transmitting uplink data(Uplink-Shared Channel: UL-SCH). In addition, the PUSCH may be used fortransmitting the HARQ-ACK and/or channel state information together withuplink data. Furthermore, the PUSCH may be used for transmitting onlychannel state information, or only the HARQ-ACK and channel stateinformation.

The PRACH is a physical channel used for transmitting a random accesspreamble. The PRACH can be used for synchronization with the basestation apparatus 1 in a time range by the terminal apparatus 2. Inaddition, the PRACH is also used to indicate an initial connectionestablishment procedure (process), a handover procedure, a connectionre-establishment procedure, synchronization with uplink transmission(timing adjustment), and/or a request for a PUSCH resource.

In a PUCCH range, a plurality of the PUCCHs is multiplexed by frequency,time, space, and/or code multiplexing. In a PUSCH range, a plurality ofthe PUSCHs may be multiplexed by frequency, time, space, and/or codemultiplexing. The PUCCH and the PUSCH may be multiplexed by frequency,time, space, and/or code multiplexing. The PRACH may be arranged in asingle sub frame or two sub frames. A plurality of the PRACHs may bemultiplexed by code multiplexing.

<Uplink Physical Signal in Present Embodiment>

UL-DMRS is associated with transmission of the PUSCH or the PUCCH. TheUL-DMRS is multiplexed with the PUSCH or the PUCCH by time multiplexing.The base station apparatus 1 may use the UL-DMRS to perform propagationpath correction of the PUSCH or the PUCCH. In the description of thepresent embodiment, transmission of the PUSCH includes transmission withmultiplexing of the PUSCH and the UL-DMRS. In the description of thepresent embodiment, transmission of PUCCH includes transmission withmultiplexing of the PUCCH and the UL-DMRS.

SRS is not associated with transmission of the PUSCH or the PUCCH. Thebase station apparatus 1 may use the SRS for measuring a channel stateof an uplink.

The SRS is transmitted using a final symbol within an uplink sub frame.In other words, the SRS is arranged in the final symbol within theuplink sub frame. The terminal apparatus 2 is capable of limitingsynchronous transmission of the SRS, the PUCCH, the PUSCH, and/or thePRACH in a certain symbol of a certain cell. The terminal apparatus 2 iscapable of transmitting the PUSCH and/or the PUCCH using symbols exceptfor a final symbol within a certain uplink sub frame in a certain cell,and transmitting the SRS using the final symbol within the uplink subframe. Accordingly, the terminal apparatus 2 is capable of transmittingthe SRS, the PUSCH, and the PUCCH in a certain uplink sub frame of acertain cell.

In an SRS, a trigger type 0SRS and a trigger type 1SRS are defined asdifferent trigger types of the SRS. The trigger type 0SRS is transmittedby upper layer signaling in a case where a parameter associated with thetrigger type 0SRS is set. The trigger type 1SRS is transmitted by upperlayer signaling in a case where a parameter associated with the triggertype 1SRS is set, with transmission requested by an SRS request includedin a DCI format 0, 1A, 2B, 2C, 2D, or 4. Note that the SRS request isincluded in both the FDD and the TDD for the DCI format 0, 1A, or 4, andincluded only in the TDD for the DCI format 2B, 2C, or 2D. In a casewhere transmission of the trigger type 0SRS and transmission of thetrigger type 1SRS occur in the same sub frame of the same serving cell,transmission of the trigger type 1SRS is given priority. The triggertype 0SRS is also referred to as periodic SRS. The trigger type 1SRS isalso referred to as aperiodic SRS.

<Configuration Example of Base Station Apparatus 1 in PresentEmbodiment>

FIG. 5 is a schematic block diagram depicting a configuration of thebase station apparatus 1 of the present embodiment. As depicted in thefigure, the base station apparatus 1 includes an upper layer processingunit 101, a control unit 103, a reception unit 105, a transmission unit107, and a transmission and reception antenna 109. Moreover, thereception unit 105 includes a decoding unit 1051, a demodulation unit1053, a demultiplexing unit 1055, a wireless reception unit 1057, and achannel measurement unit 1059. Furthermore, the transmission unit 107includes an encoding unit 1071, a modulation unit 1073, a multiplexingunit 1075, a wireless transmission unit 1077, and a downlink referencesignal generation unit 1079.

As already described, the base station apparatus 1 is capable ofsupporting the one or more RATs. A part or all of the respective unitsincluded in the base station apparatus 1 depicted in FIG. 5 may beconfigured individually in accordance with the RAT. For example, each ofthe reception unit 105 and the transmission unit 107 is individuallyconfigured using LTE and NR. In addition, in an NR cell, a part or allof the respective units included in the base station apparatus 1depicted in FIG. 5 may be individually configured in accordance with aparameter set associated with a transmission signal. For example, in acertain NR cell, each of the wireless reception unit 1057 and thewireless transmission unit 1077 may be individually configured inaccordance with a parameter set associated with a transmission signal.

The upper layer processing unit 101 performs processing for a mediumaccess control (MAC) layer, a packet data convergence protocol (PDCP)layer, a radio link control (RLC) layer, and a radio resource control(RRC) layer. In addition, the upper layer processing unit 101 generatescontrol information for controlling the reception unit 105 and thetransmission unit 107, and outputs the control information to thecontrol unit 103.

The control unit 103 controls the reception unit 105 and thetransmission unit 107 on the basis of the control information receivedfrom the upper layer processing unit 101. The control unit 103 generatescontrol information for the upper layer processing unit 101, and outputsthe control information to the upper layer processing unit 101. Thecontrol unit 103 receives an input of a decoded signal from the decodingunit 1051, and an input of a channel estimation result from the channelmeasurement unit 1059. The control unit 103 outputs a signal to beencoded to the encoding unit 1071. In addition, the control unit 103 isused to control the whole or a part of the base station apparatus 1.

The upper layer processing unit 101 performs processing and managementassociated with RAT control, radio resource control, sub frame setting,scheduling control, and/or CSI report control. The processing andmanagement by the upper layer processing unit 101 is performed for eachterminal apparatus, or in common to terminal apparatuses connected tothe base station apparatus. The processing and management by the upperlayer processing unit 101 may be performed only by the upper layerprocessing unit 101, or may be acquired from an upper node or anotherbase station apparatus. In addition, the processing and management bythe upper layer processing unit 101 may be performed individually inaccordance with the RAT. For example, the upper layer processing unit101 individually performs processing and management in LTE, andprocessing and the management in NR.

Management associated with the RAT is performed in the RAT control bythe upper layer processing unit 101. For example, management associatedwith LTE and/or management associated with the NR is performed in theRAT control. Management associated with NR includes setting andprocessing for a parameter set associated with a transmission signal inan NR cell.

In the radio resource control by the upper layer processing unit 101,generation and/or management for downlink data (transport block), systeminformation, an RRC message (RRC parameter), and/or an MAC controlelement (CE) is performed.

In the sub frame setting by the upper layer processing unit 101,management of sub frame setting, sub frame pattern setting,uplink-downlink setting, uplink reference UL-DL setting, and/or downlinkreference UL-DL setting is performed. Note that the sub frame setting bythe upper layer processing unit 101 is also referred to as base stationsub frame setting. Moreover, the sub frame setting by the upper layerprocessing unit 101 can be determined on the basis of a traffic volumeof uplinks and a traffic volume of downlinks. Furthermore, the sub framesetting by the upper layer processing unit 101 can be determined on thebasis of a scheduling result of scheduling control by the upper layerprocessing unit 101.

In the scheduling control by the upper layer processing unit 101, afrequency and a sub frame to which a physical channel is allocated, anencoding rate of a physical channel, a modulation method, transmissionpower, and others are determined on the basis of received channel stateinformation, an estimation value of a propagation path and channelquality input from the channel measurement unit 1059, and the like. Forexample, the control unit 103 generates control information (DCI format)on the basis of a scheduling result of the scheduling control by theupper layer processing unit 101.

In the CSI report control by the upper layer processing unit 101, a CSIreport of the terminal apparatus 2 is controlled. For example, settingassociated with a CSI reference resource for an assumption forcalculating CSI by the terminal apparatus 2 is controlled.

The reception unit 105 receives a signal transmitted from the terminalapparatus 2 via the transmission and reception antenna 109 under controlby the control unit 103, and further performs a reception process suchas separation, demodulation, and decoding, and outputs informationsubjected to the reception process to the control unit 103. Note thatthe reception process by the reception unit 105 is performed on thebasis of setting specified in advance, or setting of a notice given fromthe base station apparatus 1 to the terminal apparatus 2.

The wireless reception unit 1057 performs, for an uplink signal receivedvia the transmission and reception antenna 109, conversion to anintermediate frequency (down conversion), removal of an unnecessaryfrequency component, control of an amplification level in such a manneras to maintain an appropriate signal level, quadrature demodulationbased on an in-phase component and a quadrature component of thereceived signal, conversion from an analog signal to a digital signal,removal of guard interval (GI), and/or extraction of a frequency rangesignal by fast Fourier transform (FFT).

The demultiplexing unit 1055 separates an uplink channel such as thePUCCH or the PUSCH and/or an uplink reference signal from a signal inputfrom the wireless reception unit 1057. The demultiplexing unit 1055outputs an uplink reference signal to the channel measurement unit 1059.The demultiplexing unit 1055 compensates for a propagation path for theuplink channel on the basis of a propagation path estimation value inputfrom the channel measurement unit 1059.

The demodulation unit 1053 demodulates a reception signal for amodulation symbol of the uplink channel using a modulation method suchas BPSK (Binary Phase Shift Keying), QPSK (Quadrature Phase ShiftKeying), 16 QAM (Quadrature Amplitude Modulation), 64 QAM, and 256 QAM.The demodulation unit 1053 separates and demodulates a MIMO-multiplexeduplink channel.

The decoding unit 1051 performs a decoding process for encoded bits of ademodulated uplink channel. Uplink data and/or uplink controlinformation after decoding is output to the control unit 103. Thedecoding unit 1051 performs the decoding process for the PUSCH for eachtransport block.

The channel measurement unit 1059 measures a propagation path estimationvalue and/or channel quality, for example, on the basis of an uplinkreference signal input from the demultiplexing unit 1055, and outputs ameasurement result to the demultiplexing unit 1055 and/or the controlunit 103. For example, the channel measurement unit 1059 measures apropagation path estimation value used for propagation path compensationfor the PUCCH or the PUSCH using the UL-DMRS, and measures channelquality of an uplink using the SRS.

The transmission unit 107 performs a transmission process such asencoding, modulation, and multiplexing for downlink control informationand downlink data input from the upper layer processing unit 101 undercontrol by the control unit 103. For example, the transmission unit 107generates and multiplexes a PHICH, the PDCCH, the EPDCCH, the PDSCH, anda downlink reference signal to generate a transmission signal. Note thatthe transmission process by the transmission unit 107 is performed onthe basis of setting specified in advance, a notice of setting givenfrom the base station apparatus 1 to the terminal apparatus 2, or anotice of setting given via the PDCCH or the EPDCCH transmitted in anidentical sub frame.

The encoding unit 1071 encodes an HARQ indicator (HARQ-ACK), downlinkcontrol information, and downlink data input from the control unit 103using a predetermined encoding method such as block encoding,convolution encoding, and turbo encoding. The modulation unit 1073modulates encoded bits input from the encoding unit 1071 using apredetermined modulation method such as BPSK, QPSK, 16 QAM, 64 QAM, and256 QAM. The downlink reference signal generation unit 1079 generates adownlink reference signal on the basis of a physical cell identification(PCI), an RRC parameter set for the terminal apparatus 2 or the like.The multiplexing unit 1075 multiplexes modulation symbols of respectivechannels with the downlink reference signal, and arranges themultiplexed result in a predetermined resource element.

The wireless transmission unit 1077 performs, for a signal received fromthe multiplexing unit 1075, conversion into a time range signal byinverse fast Fourier transform (IFFT), addition of a guard interval,generation of a baseband digital signal, conversion into an analogsignal, quadrature modulation, conversion from an intermediate frequencysignal to a high frequency signal (up conversion), removal of an extrafrequency component, amplification of power, and other processes togenerate a transmission signal. The transmission signal output from thewireless transmission unit 1077 is transmitted from the transmission andreception antenna 109.

<Configuration Example of Terminal Apparatus 2 in Present Embodiment>

FIG. 6 is a schematic block diagram depicting a configuration of theterminal apparatus 2 of the present embodiment. As depicted in thefigure, the terminal apparatus 2 includes an upper layer processing unit201, a control unit 203, a reception unit 205, a transmission unit 207,and a transmission and reception antenna 209. Moreover, the receptionunit 205 includes a decoding unit 2051, a demodulation unit 2053, ademultiplexing unit 2055, a wireless reception unit 2057, and a channelmeasurement unit 2059. Furthermore, the transmission unit 207 includesan encoding unit 2071, a modulation unit 2073, a multiplexing unit 2075,a wireless transmission unit 2077, and an uplink reference signalgeneration unit 2079.

As already described, the terminal apparatus 2 is capable of supportingone or more RATs. A part or all of the respective units included in theterminal apparatus 2 depicted in FIG. 6 may be configured individuallyin accordance with the RAT. For example, each of the reception unit 205and the transmission unit 207 is individually configured using LTE andNR. In addition, in an NR cell, a part or all of the respective unitsincluded in the terminal apparatus 2 depicted in FIG. 6 may beindividually configured in accordance with a parameter set associatedwith a transmission signal. For example, in a certain NR cell, each ofthe wireless reception unit 2057 and the wireless transmission unit 2077may be individually configured in accordance with a parameter setassociated with a transmission signal.

The upper layer processing unit 201 outputs uplink data (transportblock) to the control unit 203. The upper layer processing unit 201performs processing for a medium access control (MAC) layer, a packetdata convergence protocol (PDCP) layer, a radio link control (RLC)layer, and a radio resource control (RRC) layer. In addition, the upperlayer processing unit 201 generates control information for controllingthe reception unit 205 and the transmission unit 207, and outputs thecontrol information to the control unit 203.

The control unit 203 controls the reception unit 205 and thetransmission unit 207 on the basis of the control information receivedfrom the upper layer processing unit 201. The control unit 203 generatescontrol information for the upper layer processing unit 201, and outputsthe control information to the upper layer processing unit 201. Thecontrol unit 203 receives an input of a decoded signal from the decodingunit 2051, and an input of a channel estimation result from the channelmeasurement unit 2059. The control unit 203 outputs a signal to beencoded to the encoding unit 2071. In addition, the control unit 203 maybe used to control the whole or a part of the terminal apparatus 2.

The upper layer processing unit 201 performs processing and managementassociated with RAT control, radio resource control, sub frame setting,scheduling control, and/or CSI report control. The processing andmanagement by the upper layer processing unit 201 is performed on thebasis of setting specified in advance, and/or setting based on controlinformation set or given as a notice by the base station apparatus 1.For example, the control information given from the base stationapparatus 1 includes an RRC parameter, an MAC control element, or DCI.In addition, the processing and management by the upper layer processingunit 201 may be performed individually in accordance with the RAT. Forexample, the upper layer processing unit 201 individually performsprocessing and management in LTE, and processing and the management inNR.

In the RAT control by the upper layer processing unit 201, managementassociated with the RAT is performed. For example, management associatedwith LTE and/or management associated with NR is performed in the RATcontrol. The management associated with NR includes setting andprocessing for a parameter set associated with a transmission signal inan NR cell.

In the radio resource control by the upper layer processing unit 201,management of setting information associated with the own apparatus isperformed. In the radio resource control by the upper layer processingunit 201, generation and/or management of uplink data (transport block),system information, an RRC message (RRC parameter), and/or an MACcontrol element (CE) is performed.

In the sub frame setting by the upper layer processing unit 201, subframe setting for the base station apparatus 1 and/or a base stationapparatus different from the base station apparatus 1 is managed. Thesub frame setting includes setting of an uplink or a downlink for a subframe, sub frame pattern setting, uplink-downlink setting, uplinkreference UL-DL setting, and/or downlink reference UL-DL setting. Notethat the sub frame setting by the upper layer processing unit 201 isalso referred to as terminal sub frame setting.

In the scheduling control by the upper layer processing unit 201,control information used for performing control associated withscheduling of the reception unit 205 and the transmission unit 207 isgenerated on the basis of DCI (scheduling information) from the basestation apparatus 1.

In the CSI report control by the upper layer processing unit 201,control associated with a CSI report for the base station apparatus 1 isperformed. For example, in the CSI report control, setting associatedwith a CSI reference resource for an assumption for calculating CSI bythe channel measurement unit 2059 is controlled. In the CSI reportcontrol, a resource (timing) used for reporting CSI is controlled on thebasis of a DCI and/or an RRC parameter.

The reception unit 205 receives a signal transmitted from the basestation apparatus 1 via the transmission and reception antenna 209 undercontrol by the control unit 203, and further performs a receptionprocess such as separation, demodulation, and decoding, and outputsinformation subjected to the reception process to the control unit 203.Note that the reception process by the reception unit 205 is performedon the basis of setting specified in advance, or a notice or settinggiven from the base station apparatus 1.

The wireless reception unit 2057 performs, for an uplink signal receivedvia the transmission and reception antenna 209, conversion to anintermediate frequency (down conversion), removal of an unnecessaryfrequency component, control of an amplification level in such a manneras to maintain an appropriate signal level, quadrature demodulationbased on an in-phase component and a quadrature component of thereceived signal, conversion from an analog signal to a digital signal,removal of guard interval (GI), and/or extraction of a signal in afrequency range by fast Fourier transform (FFT).

The demultiplexing unit 2055 separates a downlink channel such as thePHICH, the PDCCH, the EPDCCH, and the PDSCH, a downlink synchronizationsignal, and/or a downlink reference signal from a signal input from thewireless reception unit 2057. The demultiplexing unit 2055 outputs thedownlink reference signal to the channel measurement unit 2059. Thedemultiplexing unit 2055 compensates for a propagation path for thedownlink channel on the basis of a propagation path estimation valueinput from the channel measurement unit 2059.

The demodulation unit 2053 demodulates a reception signal for amodulation symbol of the downlink channel using a modulation method suchas BPSK, QPSK, 16 QAM, 64 QAM, and 256 QAM. The demodulation unit 2053separates and demodulates a MIMO-multiplexed downlink channel.

The decoding unit 2051 performs a decoding process for encoded bits of ademodulated downlink channel. Downlink data and/or downlink controlinformation after decoding is output to the control unit 203. Thedecoding unit 2051 performs the decoding process for the PDSCH for eachtransport block.

The channel measurement unit 2059 measures a propagation path estimationvalue and/or channel quality, for example, on the basis of a downlinkreference signal input from the demultiplexing unit 2055, and outputsthe measurement result to the demultiplexing unit 2055 and/or thecontrol unit 203. The downlink reference signal used by the channelmeasurement unit 2059 for measurement may be determined on the basis ofat least a transmission mode and/or another RRC parameter set by the RRCparameter. For example, the DL-DMRS measures a propagation pathestimation value for propagation path compensation for the PDSCH or theEPDCCH. The CRS measures a propagation path estimation value forpropagation path compensation for the PDCCH or the PDSCH, and/or achannel of a downlink for reporting the CSI. The CSI-RS measures achannel of a downlink for reporting the CSI. The channel measurementunit 2059 calculates RSRP (Reference Signal Received Power) and/or RSRQ(Reference Signal Received Quality) on the basis of the CRS, the CSI-RS,or a detection signal, and outputs a calculation result to the upperlayer processing unit 201.

The transmission unit 207 performs a transmission process such asencoding, modulation, and multiplexing for uplink control informationand uplink data input from the upper layer processing unit 201 undercontrol by the control unit 203. For example, the transmission unit 207generates and multiplexes an uplink channel such as the PUSCH and thePUCCH, and/or an uplink reference signal, and generates a transmissionsignal. Note that the transmission process by the transmission unit 207is performed on the basis of setting specified in advance, or setting ora notice given from the base station apparatus 1.

The encoding unit 2071 encodes an HARQ indicator (HARQ-ACK), uplinkcontrol information, and uplink data input from the control unit 203using a predetermined encoding method such as block encoding,convolution encoding, and turbo encoding. The modulation unit 2073modulates encoded bits input from the encoding unit 2071 using apredetermined modulation method such as BPSK, QPSK, 16 QAM, 64 QAM, and256 QAM. The uplink reference signal generation unit 2079 generates anuplink reference signal on the basis of an RRC parameter set for theterminal apparatus 2 or the like. The multiplexing unit 2075 multiplexesmodulation symbols of the respective channels with the uplink referencesignal, and arranges the multiplexed result in a predetermined resourceelement.

The wireless transmission unit 2077 performs, for a signal received fromthe multiplexing unit 2075, processes such as conversion into a timerange signal by inverse fast Fourier transform (IFFT), addition of aguard interval, generation of a baseband digital signal, conversion intoan analog signal, quadrature modulation, conversion from an intermediatefrequency signal to a high frequency signal (up conversion), removal ofan extra frequency component, and amplification of power to generate atransmission signal. The transmission signal output from the wirelesstransmission unit 2077 is transmitted from the transmission andreception antenna 209.

<Signaling of Control Information in Present Embodiment>

Each of the base station apparatus 1 and the terminal apparatus 2 isallowed to use various methods for signaling (notice, notification, andsetting) of corresponding control information. The signaling of thecontrol information is allowed to be performed in various layers. Thesignaling of the control information includes physical layer signalingas signaling through a physical layer, RRC signaling as signalingthrough an RRC layer, and MAC signaling as signaling through an MAClayer, for example. The RRC signaling is dedicated RRC signaling forgiving a notice of control information peculiar to the terminalapparatus 2, or common RRC signaling for giving a notice of controlinformation peculiar to the base station apparatus 1. Signaling used byan upper layer as viewed from a physical layer, such as the RRCsignaling and the MAC signaling, is also referred to as upper layersignaling.

The RRC signaling is implemented by signaling an RRC parameter. The MACsignaling is implemented by signaling an MAC control element. Thephysical layer signaling is implemented by signaling downlink controlinformation (DCI) or uplink control information (UCI). The RRC parameterand the MAC control element are transmitted using the PDSCH or thePUSCH. The DCI is transmitted using the PDCCH or the EPDCCH. The UCI istransmitted using the PUCCH or the PUSCH. Each of the RRC signaling andthe MAC signaling is used for signaling semi-static control information,and is also referred to as semi-static signaling. The physical layersignaling is used for signaling dynamic control information, and alsoreferred to as dynamic signaling. The DCI is used for scheduling thePDSCH or scheduling the PUSCH. The UCI is used for a CSI report, anHARQ-ACK report, and/or a scheduling request (SR), for example.

<Details of Downlink Control Information in Present Embodiment>

A notice of the DCI is given using a DCI format having a field specifiedin advance. Predetermined information bits are mapped in the fieldspecified in the DCI format. The DCI gives a notice of downlinkscheduling information, uplink scheduling information, side linkscheduling information, a request for an aperiodic CSI report, or anuplink transmission power command.

The DCI format monitored by the terminal apparatus 2 is determined inaccordance with a transmission mode set for each serving cell. In otherwords, a part of the DCI format monitored by the terminal apparatus 2 isallowed to vary in accordance with the transmission mode. For example,the terminal apparatus 2 for which a downlink transmission mode 1 hasbeen set monitors a DCI format 1A and a DCI format 1. For example, theterminal apparatus 2 for which a downlink transmission mode 4 has beenset monitors the DCI format 1A and a DCI format 2. For example, theterminal apparatus 2 for which an uplink transmission mode 1 has beenset monitors a DCI format 0. For example, the terminal apparatus 2 forwhich an uplink transmission mode 2 has been set monitors the DCI format0 and a DCI format 4.

A notice of a control range where the PDCCH used to give a notice of theDCI for the terminal apparatus 2 is arranged is not given. The terminalapparatus 2 detects the DCI for the terminal apparatus 2 by blinddecoding (blind detection). More specifically, the terminal apparatus 2monitors a set of PDCCH candidates in the serving cell. Monitoringrefers to an attempt of decoding each PDCCH in the set by using all theDCI formats to be monitored. For example, the terminal apparatus 2attempts decoding of all aggregation levels, the PDCCH candidates, andthe DCI formats likely to be transmitted to the destination of theterminal apparatus 2. The terminal apparatus 2 recognizes the DCI(PDCCH) for which decoding (detection) has succeeded as the DCI (PDCCH)for the terminal apparatus 2.

Cyclic redundancy check (CRC) is added to the DCI. The CRC is used forerror detection of the DCI and blind detection of the DCI. The CRC (CRCparity bits) is scrambled in accordance with an RNTI (Radio NetworkTemporary Identifier). The terminal apparatus 2 detects whether thecorresponding DCI is DCI for the terminal apparatus 2 on the basis ofthe RNTI. More specifically, the terminal apparatus 2 descrambles bitscorresponding to the CRC by the predetermined RNTI, extracts the CRC,and detects whether the corresponding DCI is correct.

The RNTI is specified or set in accordance with purposes or applicationsof the DCI. The RNTI includes a C-RNTI (Cell-RNTI), an SPS C-RNTI (SemiPersistent Scheduling C-RNTI), an SI-RNTI (System Information-RNTI), aP-RNTI (Paging-RNTI), an RA-RNTI (Random Access-RNTI), a TPC-PUCCH-RNTI(Transmit Power Control-PUCCH-RNTI), a TPC-PUSCH-RNTI (Transmit PowerControl-PUSCH-RNTI), a temporary C-RNTI, an M-RNTI (MBMS (MultimediaBroadcast Multicast Services)-RNTI), and an eIMTA-RNTI and a CC-RNTI.

Each of the C-RNTI and the SPS C-RNTI is a RNTI peculiar to the terminalapparatus 2 within the base station apparatus 1 (cell), and functions asan identifier for identifying the terminal apparatus 2. The C-RNTI isused for scheduling the PDSCH or the PUSCH in a certain sub frame. TheSPS C-RNTI is used to activate or release cyclic scheduling of aresource for the PDSCH or the PUSCH. A control channel which has CRCscrambled by the SI-RNTI is used for scheduling an SIB (SystemInformation Block). A control channel which has CRC scrambled by theP-RNTI is used for controlling paging. A control channel which has CRCscrambled by the RA-RNTI is used for scheduling a response to RACH. Acontrol channel which has CRC scrambled by the TPC-PUCCH-RNTI is usedfor power control of the PUCCH. A control channel which has CRCscrambled by the TPC-PUSCH-RNTI is used for power control of the PUSCH.A control channel which has CRC scrambled by the Temporary C-RNTI isused by a mobile station apparatus for which the C-RNTI is not set orrecognized. A control channel which has CRC scrambled by the M-RNTI isused for scheduling MBMS. A control channel which has CRC scrambled bythe eIMTA-RNTI is used for giving a notice of information associatedwith TDD UL/DL setting in a TDD serving cell in dynamic TDD (eIMTA). Acontrol channel (DCI) which has CRC scrambled by the CC-RNTI is used forgiving a notice of setting of a dedicated OFDM symbol in an LAAsecondary cell. Note that the DCI format may be scrambled by a new RNTIinstead of the RNTIs described above.

The scheduling information (downlink scheduling information, uplinkscheduling information, and side link scheduling information) includesinformation used for scheduling in units of a resource block or aresource block group as scheduling of a frequency range. The resourceblock group is a set of successive resource blocks, and indicates aresource allocated to the terminal apparatus to be scheduled. A size ofthe resource block group is determined in accordance with a systembandwidth.

<Details of Downlink Control Channel in Present Embodiment>

The DCI is transmitted using a control channel such as the PDCCH and theEPDCCH. The terminal apparatus 2 monitors a set of the PDCCH candidatesand/or a set of the EPDCCH candidates in one or a plurality of activatedserving cells set by RRC signaling. Monitoring herein is an attempt ofdecoding the PDCCH and/or the EPDCCH within a set corresponding to allDCI formats to be monitored.

The set of the PDCCH candidates or the set of the EPDCCH candidates arealso referred to as a search space. A common search space (CSS) and aterminal specific search space (USS) are defined in the search space.The CSS may be defined only for the search space associated with thePDCCH.

The CSS (Common Search Space) is a search space set on the basis of aparameter peculiar to the base station apparatus 1 and/or a parameterspecified beforehand. For example, the CSS is a search space used incommon by a plurality of terminal apparatuses. Accordingly, by mapping acontrol channel common to a plurality of terminal apparatuses to the CSSby the base station apparatus 1, reduction of the resource used fortransmitting the control channel is achievable.

An USS (UE-specific Search Space) is a search space set using at least aparameter peculiar to the terminal apparatus 2. In this case, the USS isa search space peculiar to the terminal apparatus 2, wherefore the basestation apparatus 1 is allowed to individually transmit a controlchannel peculiar to the terminal apparatus 2 using the USS. Accordingly,the base station apparatus 1 capable of efficiently mapping controlchannels peculiar to a plurality of terminal apparatuses.

The USS may be so set as to be usable in common to a plurality ofterminal apparatuses. For setting the USS common to the plurality ofterminal apparatuses, the parameter peculiar to the terminal apparatus 2is set to an identical parameter between a plurality of terminalapparatuses. For example, the identical parameter of the plurality ofterminal apparatuses is set in units of a cell, a transmission point, agroup of predetermined terminal apparatuses or the like.

The search space for each aggregation level is defined by a set of PDCCHcandidates. Each PDCCH is transmitted using an aggregation of one ormore CCEs (Control Channel Elements). The number of CCEs used for onePDCCH is also referred to as an aggregation level. For example, thenumber of the CCEs used for one PDCCH is 1, 2, 4, or 8.

The number of the PDCCHs candidates is determined on the basis of atleast the search space and the aggregation level. For example, in theCSS, the numbers of the PDCCH candidates at aggregation levels 4 and 8are 4 and 2, respectively. For example, in the USS, the numbers of thePDCCH candidates at aggregation levels 1, 2, 4, and 8 are 6, 6, 2, and2, respectively.

<Details of Resource Allocation in Present Embodiment>

The base station apparatus 1 is allowed to use a plurality of methods ofresource allocation of the PDSCH and/or the PUSCH to the terminalapparatus 2. The methods of the resource allocation include dynamicscheduling, semi-persistent scheduling, multi-sub-frame scheduling, andcross-sub-frame scheduling.

In the dynamic scheduling, one DCI performs resource allocation to onesub frame. More specifically, the PDCCH or the EPDCCH in a certain subframe performs scheduling of the PDSCH in the corresponding sub frame.The PDCCH or the EPDCCH in a certain sub frame performs scheduling forthe PUSCH in a predetermined sub frame after the corresponding subframe.

In the multi-sub-frame scheduling, one DCI performs resource allocationto one or more sub frames. More specifically, the PDCCH or the EPDCCH ina certain sub frame performs scheduling for the PDSCH in one or more subframes a predetermined number after the corresponding sub frame. ThePDCCH or the EPDCCH in a certain sub frame performs scheduling for thePUSCH in one or more sub frames a predetermined number after thecorresponding sub frame. The predetermined number may be an integerequal to or larger than zero. The predetermined number may be specifiedbeforehand, or determined on the basis of physical layer signalingand/or RRC signaling. In the multi-sub-frame scheduling, successive subframes may be scheduled, or a sub frame having a predetermined cycle maybe scheduled. The number of sub frames to be scheduled may be specifiedbeforehand, or determined on the basis of physical layer signalingand/or RRC signaling.

In the cross-sub-frame scheduling, one DCI performs resource allocationto one sub frame. More specifically, the PDCCH or the EPDCCH in acertain sub frame schedules the PDSCH in one sub frame a predeterminednumber after the corresponding sub frame. The PDCCH or the EPDCCH in acertain sub frame schedules the PUSCH in one sub frame a predeterminednumber after the corresponding sub frame. The predetermined number maybe an integer equal to or larger than zero. The predetermined number maybe specified beforehand, or determined on the basis of physical layersignaling and/or RRC signaling. In the cross-sub-frame scheduling,successive sub frames may be scheduled, or a sub frame having apredetermined cycle may be scheduled.

In the semi-persistent scheduling (SPS), one DCI performs resourceallocation to one or more sub frames. Information associated with SPS isset by RRC signaling for the terminal apparatus 2. In a case where thePDCCH or the EPDCCH for enabling the SPS is detected, the terminalapparatus 2 enables processing associated with SPS, and receives thepredetermined PDSCH and/or PUSCH on the basis of setting associated withthe SPS. In a case where the PDCCH or the EPDCCH for releasing the SPSis detected in the enabled state of the SPS, the terminal apparatus 2releases (disables) the SPS, and stops reception of the predeterminedPDSCH and/or PUSCH. The SPS may be released on the basis of a case wherea predetermined condition has been met. For example, the SPS is releasedin a case where a predetermined number of pieces of blank-transmissiondata are received. The blank-transmission of data for releasing the SPScorresponds to an MAC PDU (Protocol Data Unit) including a zero MAC SDU(Service Data Unit).

The information associated with SPS set by the RRC signaling includesinformation associated with a scheduled cycle (interval) of the SPSC-RNTI as a RNTI of SPS, and the PDSCH, a scheduled cycle (interval) ofthe PUSCH, information associated with setting for releasing SPS, and/oran HARQ process number in SPS. SPS is supported only by a primary celland/or a primary secondary cell.

<Self-Contained Transmission>

In NR, transmission of a physical channel and/or a physical signal maybe transmitted by self-contained transmission. FIG. 15 depicts anexample of a frame configuration of self-contained transmission of thepresent embodiment. In the self-contained transmission, one transmissionand reception includes downlink transmission successive from a head, GP,and successive downlink transmission performed in this order. Thesuccessive downlink transmission includes at least one downlink controlinformation and the DMRS. The downlink control information instructsreception of a downlink physical channel included in the successivedownlink transmission, or transmission of an uplink physical channelincluded in the successive uplink transmission. In a case where thedownlink control information instructs reception of a downlink physicalchannel, the terminal apparatus 2 attempts reception of thecorresponding downlink physical channel on the basis of the downlinkcontrol information. Thereafter, the terminal apparatus 2 transmitssuccess or failure of reception of the downlink physical channel(success or failure of decoding) through an uplink control channelincluded in uplink transmission allocated after GP. On the other hand,in a case where the downlink control information instructs transmissionof an uplink physical channel, the terminal apparatus 2 performstransmission while inserting an uplink physical channel transmitted onthe basis of the downlink control information into the uplinktransmission. In this manner, a quick response to an increase ordecrease in a traffic ratio of the uplink and the downlink is achievableby flexible switching between uplink data transmission and downlink datatransmission in accordance with the downlink control information. Inaddition, low-delay communication of the downlink is achievable bygiving a notice of success or failure of reception of the downlink byuplink transmission immediately after the reception of the downlink.

The unit slot time is a minimum time unit defining downlinktransmission, GP, or uplink transmission. The unit slot time is reservedfor any one of downlink transmission, GP, and uplink transmission. Theunit slot time does not include both the downlink transmission and theuplink transmission at a time. The unit slot time may be a minimumtransmission time of a channel associated with DMRS included in the unitslot time. For example, the one unit slot time is defined by a samplinginterval (Ts) of NR, or an integral multiple of the symbol length.

The unit frame time may be a minimum time designated by scheduling. Theunit frame time may be a minimum unit in which a transport block istransmitted. The unit slot time may be a maximum transmission time of achannel associated with DMRS included in the unit slot time. The unitframe time may be a unit time determining uplink transmission power ofthe terminal apparatus 2. The unit frame time may be referred to as asub frame. There are three types of transmission in view of the unitframe time, i.e., a unit frame time for only downlink transmission, aunit frame time for only uplink transmission, and a unit frame time fora combination of the uplink transmission and the downlink transmission.For example, the one unit frame time is defined as an integral multipleof the sampling interval of NR (Ts), the symbol length, or the unit slottime.

The transmission and reception time is a time of one process oftransmission and reception. A time between one process of transmissionand reception and another process of transmission and reception isoccupied by a time (gap) when none of physical channels and physicalsignals is transmitted. The terminal apparatus 2 need not average CSImeasurement between different processes of transmission and reception.The transmission and reception time may be referred to as TTI. Forexample, the one transmission and reception time is defined as anintegral multiple of the sampling interval of NR (Ts), the symbollength, the unit slot time, or the unit frame time.

<Uplink RS of NR in Present Embodiment>

Examples of uplink RS in NR include NR-SRS. An example of NR-SRS will behereinafter described. Note that characteristics not specified in thefollowing description are considered similar to those of SRS in LTE.

The NR-SRS is not required to be transmitted by a final symbol within asub frame or within a slot. For example, the NR-SRS may be transmittedby an initial symbol or an intermediate symbol within a sub frame orwithin a slot.

In addition, the NR-SRS may be successively transmitted by a pluralityof symbols. For example, the NR-SRS may be transmitted by final severalsymbols within a sub frame or within a slot.

<Antenna Configuration of NR in Present Embodiment>

It is assumed that an antenna of NR has a digital antenna configuration,an analog antenna configuration, and a hybrid antenna configurationcombining the digital antenna configuration and the analog antennaconfiguration.

The digital antenna configuration is a configuration which controls anantenna weight for each antennal element using a digital circuit(baseband range).

FIG. 8 is a schematic block diagram depicting an example of the digitalantenna configuration in the present embodiment. FIG. 8 depicts theconfiguration of the base station apparatus 1 in FIG. 5 , focusing onthe configurations of the multiplexing unit 1075, the wirelesstransmission unit 1077, and the antenna unit 109. In addition, FIG. 8does not depict configurations unnecessary for description of the basicconfiguration. However, it is assumed that the respective units includethe configurations described with reference to FIG. 5 .

In the digital antenna configuration, the multiplexing unit 1075includes a precoding unit. More specifically, in the digital antennaconfiguration, a beam is formed by multiplying a transmission signalcorresponding to each antenna element by an antenna weight in theprecoding unit.

In the digital antenna configuration, flexible phase control isachievable for each antenna element, wherefore different beams can begenerated in the frequency range. Meanwhile, the digital antennaconfiguration tends to become complicated.

FIG. 9 is a schematic block diagram depicting an example of the analogantenna configuration in the present embodiment. Similarly to FIG. 8 ,FIG. 9 depicts the configuration of the base station apparatus 1 in FIG.5 , focusing on the configurations of the multiplexing unit 1075, thewireless transmission unit 1077, and the antenna unit 109. In addition,FIG. 9 does not depict configurations unnecessary for description of thebasic configuration. However, it is assumed that the respective unitsinclude the configurations described with reference to FIG. 5 .

In the analog antenna configuration, the wireless transmission unit 1077includes a phase control unit. A beam is formed by rotating a phase of atransmission signal in the analog range (RF range) using the phasecontrol unit.

In the case of the phase control in the analog range, flexible beamcontrol requires complicated processing. However, the configurationtends to become simple. In an example, an antenna switchingconfiguration is a part of the analog antenna configuration.

The hybrid antenna configuration is a configuration combining thedigital antennal configuration and the analog antenna configuration, andtherefore has both phase control elements in the analog range, and phasecontrol elements in the digital range. The hybrid antenna configurationhas intermediate characteristics between the digital antennaconfiguration and the analog antenna configuration in view ofperformance and configuration complexity of beam forming.

<Beam Operation Method of NR in Present Embodiment>

Two types of methods, i.e., a single beam operation and a plural beamoperation are assumed for NR.

For example, FIG. 10 is an explanatory diagram for explaining an outlineof an example of the single beam operation. The single beam operation isa method which covers a predetermined cell coverage by one beam (i.e.,method operated by one beam). More specifically, a physical channel or aphysical signal peculiar to a cell is transmitted by one beam within apredetermined cell coverage. For example, LTE is also considered as thesingle beam operation.

In addition, FIG. 11 is an explanatory diagram for explaining an outlineof an example of the plural beam operation. The plural beam operation isa method which covers a predetermined cell coverage by one or more beams(i.e., method operated by one or more beams). More specifically, aphysical channel or a physical signal peculiar to a cell is transmittedby a plurality of beams. For example, in cases of analog beam formingand hybrid beam forming, a beam in a predetermined direction istransmitted in a predetermined time instance, and transmission of beamsother than the beam in the predetermined direction becomes difficult.Accordingly, switching between beams in a plurality of directions, andcovering a wide range are achievable by switching the time instance, forexample. More specifically, a predetermined beam for transmitting aphysical channel or a physical signal peculiar to a cell is transmittedin one time instance (time resource). In addition, a different beam istransmitted in a different time instance. In this manner, a plurality ofbeams is switched and operated in a plurality of time instances in theplural beam operation. The switching between the plurality of beams inthe plurality of time instances is referred to as beam sweep.

Note that the plural beam operation may be performed in the digitalantenna configuration.

In addition, a beam is allowed to be converted into terms such as achannel, a path, an antenna, and an antenna port. Accordingly,transmission using different beams can be expressed as transmissionusing different channels, different paths, different antennas, ordifferent antenna ports. Furthermore, a beam is assumable as a virtualcell. The terminal apparatus is capable of recognizing different beamstransmitted from the same cell as different virtual cells or virtualcarriers. Note that information associated with the channel, the path,the antenna, the antenna port described above and allowed to beexpressed as a beam, information associated with control of the beam(e.g., information associated with setting of antenna) and others arealso collectively referred to as “antenna information” in the presentdisclosure. In this case, a signal transmitted by a predetermined beamcan be considered as a signal associated with antenna informationcorresponding to the beam.

<Appropriate Beam Selection of NR in Present Embodiment>

In NR, the system preferably selects an appropriate beam for each of adownlink and an uplink. More specifically, an appropriate beam ispreferably selected for each of a downlink transmission beam of the basestation apparatus and a downlink reception beam of the terminalapparatus. In addition, an appropriate beam is preferably selected foreach of an uplink transmission beam of the terminal apparatus and anuplink reception beam of the base station apparatus.

The base station apparatus is capable of recognizing an appropriatedownlink transmission beam on the basis of a report or feedbackinformation from the terminal apparatus which receives a signaltransmitted from the base station apparatus. An example of a processperformed by the base station apparatus for recognizing an appropriatedownlink transmission beam will be hereinafter described. For example,the base station apparatus transmits a predetermined known signal aplurality of times using downlink transmission beams different from eachother. The terminal apparatus determines the appropriate downlink beamon the basis of reception intensity or reception quality, for example,from the known signals transmitted the plurality of times by thedownlink transmission beams different from each other, and reports orfeeds back information corresponding to the appropriate downlinktransmission beam to the base station apparatus. In this manner, thebase station apparatus is capable of recognizing the appropriatedownlink transmission beam. Note that examples of the known signalinclude various types of reference signals such as an NR-SS, an MRS, aBRS, an NR-CSI-RS, and an NR-DM-RS.

In addition, the base station apparatus in another example is capable ofrecognizing an appropriate downlink transmission beam on the basis of anappropriate uplink reception beam of the base station apparatus.

The terminal apparatus is capable of recognizing an appropriate uplinktransmission beam on the basis of a report or feedback information fromthe base station apparatus which receives a signal transmitted from theterminal apparatus. An example of a process performed by the terminalapparatus for recognizing an appropriate uplink transmission beam willbe hereinafter described. For example, the terminal apparatus transmitsa predetermined known signal a plurality of times using uplinktransmission beams different from each other. The base station apparatusdetermines the appropriate uplink beam on the basis of receptionintensity or reception quality, for example, from the known signalstransmitted the plurality of times by the uplink transmission beamsdifferent from each other, and reports or gives a notice of informationcorresponding to the appropriate uplink transmission beam to theterminal apparatus. In this manner, the terminal apparatus is capable ofrecognizing the appropriate uplink transmission beam. Note that examplesof the known signal include various reference signals such as anNR-PRACH, an NR-SRS, and an NR-DM-RS.

In addition, the terminal apparatus in another example is capable ofrecognizing an appropriate uplink transmission beam on the basis of anappropriate downlink reception beam of the terminal apparatus.

<Synchronization Signal of NR in Present Embodiment>

In NR, a synchronization signal is used for synchronization of afrequency range and/or a time range of downlinks by the terminalapparatus. The synchronization signal used in NR is referred to as anNR-SS (NR-Synchronization Signal).

The NR-SS includes at least an NR-PSS (NR-Primary SynchronizationSignal) and an NR-SSS (NR-Secondary Synchronization Signal). Note thatthe NR-SS may include an NR-TSS (NR-Third Synchronization Signal). TheNR-SS is preferably kept constant for a predetermined frequency range(frequency band) regardless of the system bandwidth.

The NR-PSS is used at least for initial synchronization of a symbolboundary for an NR cell. Note that the NR-PSS may be used for detectionof a part of an NR cell identifier, or may be used for demodulation ofan NR-SSS. A sequence of the NR-PSS is constituted by an M-sequence or aZadoff-Chu-sequence, for example.

The terminal apparatus does not detect the NR-PSS using other referencesignals. In addition, the terminal apparatus need not assume that theNR-PSS is transmitted via a TRP (Transmission and Reception Point) andan antenna port identical to those of any other downlink referencesignal.

The NR-SSS is used at least for detection of an NR cell identifier or apart of an NR cell identifier. The NR-SSS is detected while positionedwith a fixed time and frequency resource relationship with a resourceposition of the NR-PSS. This resource relationship is fixed withoutdependency on a duplex method or a beam operation method. The NR-SSS ofthe type having the M-sequence is preferably adopted, but of the typehaving the Zadoff-Chu-sequence, gold-sequence or the like may beadopted. In addition, a plurality of the types of the sequence describedabove may be combined and used, or a plurality of sequences of the sametype and of different forming methods may be combined and used.

The terminal apparatus may detect the NR-SSS using channel stateinformation and/or information associated with an NR cell obtained bydetection of the NR-PSS. The terminal apparatus may assume that theNR-SSS is transmitted through the same antenna port as that of theNR-PSS.

The NR-TSS may be used for giving a notice of an index of asynchronization signal block. The NR-TSS may be used for giving a noticeof an index of a beam. The NR-TSS may be used for giving a notice of arepeating number of a synchronization signal block. The NR-TSS may beused for giving a notice of whether or not a part or all of asynchronization signal block including the NR-TSS, and othersynchronization signals and/or the NR-PBCH within a synchronizationsignal burst are identical. The NR-TSS may be used for demodulation ofthe NR-PBCH. In other words, the NR-TSS may be transmitted through thesame antenna port as that of the NR-PBCH. The terminal apparatus assumesthat the NR-PBCH and the NR-TSS exhibit QCL. Note that the NR-TSS may betransmitted while included in an OFDM symbol for transmission of theNR-PBCH. An M-sequence or a gold-sequence is preferably adopted as asequence of the NR-TSS.

The NR-SS may be used for measuring quality of an NR cell in which theNR-SS is transmitted. Examples of the quality of the NR cell include aPSRP, a RSRQ, an RSSI (Received Signal Strength Indicator), an SNS(Signal to Noise Ratio), and/or an SINR (signal to Interference plusNoise Ratio).

The NR-SS is transmitted at predetermined sub carrier intervals. Thepredetermined sub carrier intervals are uniquely defined for a frequencyband (operating band).

<Notification Channel of NR in Present Embodiment>

In NR, at least one notification channel is defined. The notificationchannel is referred to as an NR-PBCH.

The NR-PBCH is used to give a notification of a part of systeminformation. The NR-PBCH is not scheduled by other control information.Information carried by the NR-PBCH has a fixed payload size. The NR-PBCHis cyclically transmitted. The information carried by the NR-PBCH isreferred to as first NR system information or NR-MIB.

The NR-MIB included in the NR-PBCH is encoded by polar codes. Note thatthe NR-MIB may be encoded by LDPC (Low-Density Parity Check) codes.Alternatively, the NR-MIB may be encoded by convolutional codes.

The NR-PBCH may be scrambled using an NR cell identifier. The terminalapparatus descrambles the NR-PBCH using an NR cell identifier. Note thatthe NR-PBCH may be scrambled using other identifiers obtained by anNR-SS. Examples of other identifiers include a beam index and a timeindex.

Resource mapping of the NR-PBCH is sequentially allocated in a frequencydirection in advance. In a specific example, symbols after modulationare sequentially allocated to a sub carrier of a head symbol in resourceelements reserved for the NR-PBCH. Then, after allocation to all subcarriers of the head symbol, the symbols after modulation aresequentially allocated to a sub carrier of a subsequent symbol. Byrepeating these steps, the symbols after modulation are allocated to allthe resource elements reserved for the NR-PBCH.

A sub carrier interval of the NR-PBCH is preferably identical to a subcarrier interval of the NR-SS.

The NR-PBCH may be transmitted while multiplexed with an RS fordemodulating the NR-PBCH. The NR-PBCH may be demodulated using this RS.Note that the NR-PBCH may be demodulated using the NR-SS. In addition,the NR-PBCH may be demodulated using a MRS.

For example, the NR-PBCH is transmitted by a primary cell. In addition,the NR-PBCH is transmitted by a stand-alone cell. Note that transmissionof the NR-PBCH by a secondary cell is not required. In addition,transmission of the NR-PBCH by a non-stand-alone cell is not required.

<Details of Control Sub Band in Present Embodiment>

A control sub band (control resource set) is a physical resource wherethe PDCCH and the NR-PDCCH are arranged. Examples of the control subband include a control sub band (common control sub band) set in commonto the terminal apparatuses connected to the corresponding base station,and a control sub band (terminal specific sub band) individually set forthe corresponding terminal apparatus.

The common control sub band is used for the PDCCH which controls thePDSCH transmitted in common to terminals of cells or in common to agroup of the terminal apparatuses. The common control sub band is set bythe NR-MIB.

Examples of the NR-PDCCH transmitted by the common control sub bandinclude the NR-PDCCH which schedules the NR-PDSCH carrying second orfollowing system information, paging, a random access response, amessage 4 and the like.

The terminal apparatus specific sub band is used for the NR-PDCCH whichcontrols the NR-PDSCH transmitted in common to a group of the terminalapparatuses or individually to the terminal apparatus using theNR-PDCCH. The terminal apparatus specific sub band is set by dedicatedRRC signaling for the terminal apparatus.

<Initial Connection Procedure in Present Embodiment>

Initial connection is a step which shifts from a state of no connectionbetween the terminal apparatus and any cell (idle state) to a state ofestablishment of connection between the terminal apparatus and any cell(connection state). Note that a step which shifts to the connectionstate from a state where the terminal apparatus is not active even aftercompletion of RRC setting with connection to a cell (inactive state) maybe considered as the initial connection.

FIG. 12 depicts an example of an initial connection procedure of theterminal apparatus. The terminal apparatus in the idle state initiallyperforms a cell selection procedure (S101 to S103). The cell selectionprocedure includes steps of synchronization signal detection and PBCHdecoding. The terminal apparatus achieves synchronization of a downlinkwith the cell on the basis of detection of a synchronization signal(S101). Subsequently, after establishment of synchronization of thedownlink, the terminal apparatus attempts decoding of the PBCH toacquire first system information (S103).

Then, the terminal apparatus acquires second system information on thebasis of the first system information included in the PBCH (S105).

Thereafter, the terminal apparatus performs a random access procedure onthe basis of the first system information and/or the second systeminformation (S107 to S113). The random access procedure includes stepsof transmission of a random access preamble, reception of a randomaccess response, transmission of a message 3, and reception ofcontention resolution. The terminal apparatus initially selects apredetermined PRACH preamble, and transmits the selected PRACH preambleto the base station apparatus (S107). Subsequently, the terminalapparatus receives a PDSCH including a random access responsecorresponding to the PRACH preamble from the base station apparatus(S109). Thereafter, the terminal apparatus transmits, to the basestation apparatus, a PUSCH including the message 3 using a resourcescheduled by a random access response grant and included in the randomaccess response (S111). Finally, the terminal apparatus receives a PDSCHincluding the contention resolution corresponding to the PUSCH from thebase station apparatus (S113).

The message 3 described above includes an RRC message indicating an RRCconnection request. The contention resolution includes an RRC message ofan RRC connection setup. In a case of reception of the RRC messageindicating the RRC connection setup, the terminal apparatus performs anRRC connection operation and shifts from an RRC idle state to an RRCconnection state. After the shift to the RRC connection state, theterminal apparatus transmits an RRC message indicating RRC connectionsetup completion to the base station apparatus. The terminal apparatusis allowed to connect with the base station apparatus by this series ofoperations.

Note that the messages of the random access preamble, the random accessresponse, the contention resolution, and the RRC connection setupcompletion are also referred to as a message 1, a message 2, the message4, and a message 5, respectively. After completion of all the steps ofthe random access procedure, the terminal apparatus is allowed to shiftto a state of connection to the cell (connection state).

Note that the random access procedure may be performed not only at theinitial connection, but also at handover, uplink synchronization, arequest for an uplink resource, a return from wireless link failure, areturn from beam link failure, and other occasions.

Note that the random access procedure depicted in FIG. 12 is alsoreferred to as a 4-step RACH procedure. Meanwhile, in a random accessprocedure referred to as a 2-step RACH procedure, the terminal apparatustransmits the message 3 along with transmission of the random accesspreamble, and the base station apparatus transmits the random accessresponse and the contention resolution in response to the receivedmessage 3 and random access preamble.

The random access preamble is transmitted in association with the PRACH.The random access response is transmitted by the PDSCH. The PDSCHincluding the random access response is scheduled by the PDCCH. Themessage 3 is transmitted by the PUSCH. The PUSCH including the message 3is scheduled by an uplink grant included in the random access response(random access response grant).

<Details of Synchronization Signal Block of NR in Present Embodiment>

In NR, a predetermined block to which one NR-PSS, one NR-SSS, and/or anNR-PBCH is transmitted (hereinafter referred to as “synchronizationsignal block”) is defined. The terminal apparatus assumes one beam fortransmitting the NR-SS and/or the NR-PBCH in a time instance of apredetermined synchronization signal block. The one NR-PSS, the oneNR-SSS, and/or the one NR-PBCH is multiplexed within the synchronizationsignal block by time-division, frequency-division, space-division,and/or code-division.

Note that an MRS (mobility RS or mobility reference signal) may beincluded in the synchronization signal block. The MRS is used at leastfor RRM measurement. The terminal apparatus measures RSRP and/or RSRQusing the MRS. The MRS may have a configuration of CSI-RS. A sequence ofthe MRS may be scrambled by a time index.

FIG. 13 depicts an example of a configuration of the synchronizationsignal block. In FIG. 13 , the NR-PSS, the NR-SSS, and the NR-PBCH aremultiplexed by time-division within the one synchronization signalblock. The terminal apparatus detects the NR-SS and receives the NR-PBCHon an assumption that the NR-SS and the NR-PBCH are transmitted at apredetermined central frequency and in a predetermined bandwidth.

In addition, a synchronization signal burst is defined in NR. FIG. 14depicts an example of configurations of a synchronization signal burstand a synchronization signal burst set. The synchronization signal burstincludes one or a plurality of synchronization signal blocks. Theexample depicted in FIG. 14 defines N synchronization signal blocks as asynchronization signal burst. The respective synchronization signalblocks included in the synchronization signal burst may be successiveblocks.

The synchronization signal set is further defined in NR. Thesynchronization signal burst set includes one or a plurality ofsynchronization signal bursts. The example depicted in FIG. 14 defines Msynchronization signal bursts as a synchronization signal burst set.

The terminal apparatus achieves synchronization with an NR cell assumingthat the synchronization signal set is cyclically transmitted. Inaddition, the terminal apparatus performs various processes assumingthat the synchronization signal burst set is cyclically transmitted.Meanwhile, the base station apparatus is not required to transmit thesynchronization signal burst set in a predetermined time instance. Theterminal apparatus assumes an initial cycle at the time of initialconnection, and attempts detection of the synchronization signal burstset. In addition, the cycle of the synchronization signal burst set maybe set by the upper layer. In a case where the cycle of thesynchronization signal burst set is set by the upper layer, the terminalapparatus may overwrite a value of the cycle set by the upper layer onthe value of the cycle set beforehand.

Note that synchronization signal burst sets transmitted in differenttime instances are not required to be transmitted through identicalantenna port and TRP.

In addition, it is preferable that one of sub frames in each of whichthe synchronization signal burst set is arranged is a sub frame #0. Inother words, it is preferable the synchronization signal burst set isdisposed in the sub frame #0. The terminal apparatus is capable ofrecognizing the sub frame number in each of times by recognizing a headof the synchronization signal burst set.

An index on a time axis (time index) is allocated to each of thesynchronization signal blocks. The time index of each of thesynchronization signal blocks is included in the correspondingsynchronization signal block and given to the terminal apparatus as anotice. The terminal apparatus is capable of recognizing a downlinktransmission beam of the base station apparatus in the synchronizationsignal block, a wireless frame, and/or a sub frame boundary on the basisof the time index of the synchronization signal block. In addition, theterminal apparatus is capable of identifying the index of thesynchronization signal block on the basis of the time index.

The time index of the synchronization signal block is an offset valuefrom a boundary of a sub frame or a slot. The time index of thesynchronization signal block in an example is indicated by an index ofan OFDM symbol. Alternatively, in another example, the time index of thesynchronization signal block may be indicated by an index of thesynchronization signal block transmitted within the synchronizationsignal burst set. In addition, in a further example, the time index maybe indicated by an index of a beam.

Examples of the notice of the time index of the synchronization signalblock include a notice by a sequence of an NR-SS.

Examples of the notice of the time index of the synchronization signalblock include a notice by a sequence of an NR-PBCH-DMRS.

Examples of the notice of the time index of the synchronization signalblock include a notice by information included in an NR-MIB.

Examples of the notice of the time index of the synchronization signalblock include a notice by a mapping position of bits of an NR-PBCH. In aspecific example, the terminal apparatus is capable of recognizing thetime index on the basis of a mapping start position of bits afterencoding of the NR-PBCH included in the synchronization signal block.

Examples of the notice of the time index of the synchronization signalblock include a notice by a mask of CRC of the NR-PBCH. In a specificexample, the NR-PBCH is transmitted after CRC bits of the NR-PBCH ismultiplied by a predetermined CRC mask corresponding to the time index.The terminal apparatus performs blind detection of the CRC mask which islikely to be multiplied by the CRC bits using CRC check. The terminalapparatus is capable of recognizing a time index by a valuecorresponding to the CRC mask for which decoding of the NR-PBCH hassucceeded as a result of the CRC check.

Examples of the notice of the time index of the synchronization signalblock include a notice by a sequence of the MRS.

Note that a notice of the time index of the synchronization signal blockis not required to be given to the terminal apparatus in a case of thesingle beam operation.

Note that a notice of the time index of the synchronization signal blockis not required to be given to the terminal apparatus by using the abovemethod in a case where synchronization signal block timing andsynchronization signal block identification are achievable. In a casewhere a notice of a time index of a synchronization signal block ofanother cell (e.g., serving cell such as a primary cell) is given fromthe other cell as a notice in an example, the time index is not requiredto be given to the terminal apparatus using the method described above.In another example where the terminal apparatus recognizes transmissionof only one type of the synchronization signal block in thecorresponding cell, a notice of the time index is not required to begiven to the terminal apparatus using the method described above.

<System Information in Present Embodiment>

System information is information which gives a notification of settingsin a cell transmitting the system information. Examples of the systeminformation include information associated with an access to the cell,information associated with cell selection, and information associatedwith another RAT and another system.

The system information is classifiable into MIB and SIB. The MIB isinformation given by a PBCH as a notification, and having a fixedpayload size. The MIB includes information for acquiring SIB. The SIB issystem information other than the MIB. The SIB is a notification givenby a PDSCH.

In addition, the system information is classifiable into first systeminformation, second system information, and third system information.Each of the first system information and the second system informationincludes information associated with an access to a corresponding cell,information associated with acquisition of other system information,information associated with cell selection, and others. In LTE,information included in the MIB is considered as the first systeminformation, and information included in SIB1 and SIB2 is considered asthe second system information. In a case where all the first systeminformation and the second system information are not acquired from acorresponding cell, the terminal apparatus assumes that an access to thecell is prohibited.

The MIB is information associated with a physical layer necessary forreceiving the system information. For example, the MIB includes a systembandwidth of a downlink, a part of a system frame number, schedulinginformation associated with the SIB, and others.

The SIB1 corresponds to information associated with cell accessregulation information, and scheduling information associated withsystem information other than the SIB1. For example, the SIB1 includescell access information, cell selection information, maximum uplinktransmission power information, TDD setting information, a cycle ofsystem information, mapping information associated with systeminformation, a length of an SI window, and others.

For example, the SIB2 includes connection prohibition information,common radio resource setting information (radioResourceConfigCommon),uplink carrier information, and others. The radio resource settinginformation common to cells include setting information associated withthe PRACH and the RACH common to cells. At the time of an initialaccess, the terminal apparatus performs a random access procedure on thebasis of setting information associated with the PRACH and the RACH.

<System Information in NR in Present Embodiment>

In NR, system information is similarly given as a notification from anNR cell. A physical channel carrying the system information may betransmitted through a slot or a mini-slot. The mini-slot is defined by asmaller number of symbols than the number of symbols of the slot. Bytransmitting the physical channel carrying the system informationthrough the minim-slot, a time necessary for beam sweeping can bereduced. Accordingly, reduction of overhead is achievable.

The first system information is transmitted by an NR-PBCH, while thesecond system information is transmitted by a physical channel differentfrom the NR-PBCH.

In NR, the first system information is preferably information peculiarto a terminal apparatus group. For example, the terminal apparatus groupis constituted by a plurality of terminal apparatuses grouped bypredetermined beams. Each of the terminal apparatuses recognizes anidentifier associated with the corresponding predetermined beam. Inaddition, for example, the terminal apparatus group is constituted by aplurality of terminal apparatuses grouped by predetermined TRPs. Each ofthe terminal apparatuses recognizes an identifier associated with thecorresponding predetermined TRP. Furthermore, for example, the terminalapparatus group is constituted by a plurality of terminal apparatusesgrouped by predetermined cells. Each of the terminal apparatusesrecognizes an identifier associated with the corresponding predeterminedcell.

The first system information includes information necessary foracquiring at least the second system information.

The first system information in an example includes schedulinginformation associated with a physical channel which carries the secondsystem information. For example, the scheduling information includes acycle and a time offset, a central frequency, a bandwidth, and others.

In addition, the first system information in an example includesinformation associated with a transmission method of a physical channelwhich carries the second system information. For example, informationused for decoding of the physical channel include the number of antennaports of the physical channel, an antenna port number, informationassociated with a transmission scheme such as SFBC (Space FrequencyBlock Coding), FSTD (Frequency-Switched Transmit Diversity), and CDD(Cyclic Delay Diversity), and information associated with CRC.

The first system information in an example includes a system framenumber. Note that the first system information may include a hypersystem frame number.

The first system information in an example includes informationassociated with a sub carrier interval and used for transmission of aphysical channel which carries at least the second system information.

The first system information in an example includes setting informationassociated with a common control sub band. For example, the settinginformation associated with the common control sub band includesinformation such as information associated with a frequency resource,and/or information associated with a time resource. For example, anotice of the frequency resource is given by an index which indicates aresource block index (RB) or a resource block group (RGB) representing aplurality of resource blocks. The RBG preferably has a size equal to orsmaller than a size of an RBG used for setting information associatedwith a terminal individual sub band. For example, a notice of the timeresource is given by the number of OFDM symbols, a frequency and anoffset of a slot, a sub frame, or a wireless frame, or others.

The first system information in an example includes informationassociated with timing within a wireless frame. The informationassociated with timing includes a time index, and/or informationindicating a first half or a second half within the wireless frame.

The first system information in an example includes informationassociated with a bandwidth or a part of a bandwidth. This informationis information associated with a downlink bandwidth used during aninitial access. In addition, this information is used for reception ofat least the second system information.

The first system information in an example includes informationindicating whether or not the first system information and the secondsystem information are associated with each other. In a case where thisinformation indicates that the first system information and the secondsystem information are associated with each other, the terminalapparatus is allowed to perform a reception process for receiving thesecond system information. On the other hand, in a case where theinformation indicates that the first system information and the secondsystem information are not associated with each other, the terminalapparatus is not required to perform the reception process for receivingthe second system information.

The first system information in an example includes informationindicating whether or not the terminal apparatus is connectable to acorresponding cell. In a case where this information indicates that theterminal apparatus is connectable to the cell, the terminal apparatus isallowed to receive at least the second system information. On the otherhand, in a case where the corresponding information indicates that theterminal apparatus is not connectable to the cell, the terminalapparatus is not required to perform the connection process, but mayperform re-selection of a cell, or connect to the cell as a secondarycell or a primary secondary cell.

The first system information in an example includes informationassociated with a cycle of a synchronization signal burst set. As thecycle of the synchronization signal burst set, any one of 5milliseconds, 10 milliseconds, 20 milliseconds, 40 milliseconds, and 80milliseconds is set in accordance with the information.

The first system information in an example includes informationassociated with a synchronization signal block actually transmitted in acorresponding cell in resources which are likely to be transmitted in asynchronization signal burst set. For example, this information isallowed to be used for determining whether or not to perform, using thecorresponding resource, RRM measurement, and/or perform monitoring of anNR-PDCCH, cyclic transmission of an uplink signal/channel to which theresource is allocated, and others.

The first system information in an example includes informationassociated with an area ID. The area ID is an identifier associated withan area. For example, this information may be used for a distinctionbetween respective pieces of system information associated with areas.On the basis of this information, the terminal apparatus is capable ofrecognizing whether or not system information associated with a cellpreviously connected and system information associated with a cell newlyconnected are identical to each other. In addition, the terminalapparatus determines whether or not to update system information on thebasis of the information. Furthermore, in a case where the systeminformation is to be updated, the terminal apparatus also updates systeminformation other than the first system information. In a case where thesystem information is not to be updated, the terminal apparatus updatesonly the first system information.

The first system information in an example includes informationassociated with a value tag. This information is used to indicatewhether or not contents of the system information have been updated in acell in which the corresponding information is transmitted. The terminalapparatus determines whether or not to update the system information onthe basis of this information.

The first system information in an example includes informationcorresponding to extension information associated with a cell ID (cellidentifier). This information is information associated withidentification of a cell and extended from a cell ID transmitted by anNR-SS.

The first system information in an example includes informationassociated with a reference signal for tracking. For example, thereference signal for tracking is a CSI-RS. Specifically, informationassociated with the reference signal for tracking is informationassociated with RE mapping or an antenna port.

In addition, the first system information includes reservation bits usedat the time of future function extension.

The first system information and/or second system information includesat least information associated with a random access procedure.Specifically, the information associated with the random accessprocedure is setting information associated with an NR-PRACH and anNR-RACH.

Examples of the setting information associated with the NR-PRACH and theNR-RACH include information associated with a sequence of the NR-PRACH,information associated with a resource of the NR-PRACH, and informationassociated with repetitive transmission of the NR-PRACH.

The second system information in an example includes informationassociated with cell selection. Examples of the information associatedwith the cell selection include setting information associated with anevaluation of cell selection, setting information associated with anaccess right of a neighbor cell, and setting information associated witha resource of an NR-SS of the neighbor cell.

Examples of the setting information associated with the evaluation ofthe cell selection include a threshold of the evaluation of the cellselection, and an offset for cell range extension.

Examples of the setting information associated with the access right ofthe neighbor cell include a list of access denied cells (black list).

Examples of the setting information associated with the resource of theNR-SS of the neighbor cell include information associated with afrequency position of the NR-SS, and information associated with a cycleof an NR-SS burst set.

Examples of the physical channel carrying the second system informationinclude an NR-SPBCH (NR-Secondary Physical Broadcast Channel). TheNR-SPBCH is a channel not scheduled by the NR-PDCCH. Information carriedby the NR-SPBCH has a fixed payload size. The NR-SPBCH is cyclicallytransmitted. The NR-SPBCH and the NR-PBCH are different from each otherin view of the payload size, the resource mapping, and the cycle.

Examples of the physical channel carrying the second system informationinclude the NR-PDSCH. The NR-PDSCH is scheduled by the NR-PDCCH to whichCRC scrambled by an SI-RNTI is added. Note that the information carriedby the NR-PDSCH is encoded by LDPC codes.

The physical channel carrying the second system information ispreferably transmitted by QPSK, but may be transmitted by othermodulation methods such as 16 QAM and 64 QAM.

In NR, the second system information is preferably information peculiarto a terminal apparatus group. For example, the terminal apparatus groupis constituted by a plurality of terminal apparatuses grouped bypredetermined beams. Each of the terminal apparatuses recognizes anidentifier associated with the corresponding predetermined beam. Forexample, the terminal apparatus group is constituted by a plurality ofterminal apparatuses grouped by predetermined TRPs. Each of the terminalapparatuses recognizes an identifier associated with the correspondingpredetermined TRP.

In NR, the physical channel carrying the second system information andthe physical channel carrying the first system information areassociated with each other. The terminal apparatus decodes the secondsystem information on the basis of the physical channel carrying thefirst system information.

FIG. 15 depicts an example of system information corresponding to asynchronization signal block. In FIG. 15 , a synchronization signalblock #1 to a synchronization signal block #N are transmitted, andsystem information #1 to system information #N are transmitted. Therespective synchronization signal blocks are associated with therespective pieces of system information such that the synchronizationsignal block #1 is associated with the system information #1, and thatthe synchronization signal block #2 is associated with the systeminformation #2. In a case of reception of a predeterminedsynchronization signal block, the terminal apparatus decodescorresponding system information on the basis of the predeterminedsynchronization signal block.

In this case, the terminal apparatus acquires the system informationassociated with the received synchronization signal block. At the sametime, the system information associated with the synchronization signalblock not received is difficult to acquire by the terminal apparatus. Inother words, the terminal apparatus acquires system information suitedfor the terminal apparatus, but need not acquire system information notsuited for the terminal apparatus.

FIG. 16 depicts an example of a sequence of system informationcorresponding to a synchronization signal block. Initially, the basestation apparatus transmits SS (synchronization signal) blocks from #1to #N. The terminal apparatus selects the SS block suited for theterminal apparatus on the basis of reception quality of the NR-SSincluded in the SS block and a decoding result of the NR-PBCH. Inaddition, the base station apparatus transmits physical channelsincluding the system information #1 to #N, respectively. The terminalapparatus receives one of the system information #1 to #N in accordancewith the information acquired from the suited SS block.

In an example of the foregoing association, a resource of a physicalchannel carrying the second system information is determined on thebasis of the physical channel carrying the first system information.

The resource of the physical channel carrying the second systeminformation in an example is instructed by NR-MIB included in theNR-PBCH. For example, the information associated with the resourceindicates a part or all of a cycle and a time offset, a bandwidth, acentral frequency or a resource block, and the repeating number oftimes.

The resource of the physical channel carrying the second systeminformation in an example is determined on the basis of a condition fordecoding of the NR-PBCH. For example, the condition includes a timeindex. More specifically, correspondence between a time and/or afrequency resource and the time index is determined, and an associatedresource is determined on the basis of a value of the time index. Theterminal apparatus attempts decoding of the physical channel several subframes after on the basis of the time index for which the NR-PBCH hasbeen detected.

The resource of the physical channel carrying the second systeminformation in an example is fixed to a predetermined resource. Forexample, the resource is always arranged in a head sub frame.

The resource of the physical channel carrying the second systeminformation in an example is scheduled by DCI of an NR-PDCCH arranged ina CSS. In this case, a common control sub band for which the CSS is setis set on the basis of the NR-MIB included in the NR-PBCH and the systeminformation, or information acquired from the NR-SS. The common controlsub band is a control sub band set in common to the terminalapparatuses, or set in common to the terminal apparatus group. Thecontrol sub band (control range or time/frequency resource used forcontrol) is a predetermined band range where the NR-PDCCH is arranged.Examples of setting information associated with the common control bandinclude setting information associated with a predetermined band range,a sub carrier interval of a control sub band, a CP length of a symbol,and setting information associated with a predetermined time section.Examples of the information associated with the predetermined band rangeinclude a bandwidth and a central frequency of the control sub band, ormapping information associated with the resource block (bitmapinformation associated with indexes of a start and an end of theresource block, and the resource block to be used). Examples of thesetting information associated with the predetermined time sectioninclude a start symbol and/or an end symbol, and the number of symbolsfrom the start or the end. Note that the band range of the commoncontrol sub band is preferably narrower than a minimum terminalapparatus reception bandwidth (e.g., 5 MHz) in a plurality of specifiedterminal apparatus reception bandwidths in view of power consumption.

A part or all of the setting information associated with the commoncontrol sub band may differ for each synchronization signal block. Inother words, setting of the common control sub band may be independentof the synchronization signal block. The physical resource of the commoncontrol sub band to be set in a specific example may differ for eachtime index.

In addition, setting information associated with the common control subband in another example is equalized in the synchronization signalblock, but the CSS of the common control sub band may be determined onthe basis of information associated with the synchronization signalblock. In other words, the position of the CSS may be determined on thebasis of the index of the corresponding synchronization signal block. Ina specific example, the CSS corresponding to the synchronization signalblock #0 may be started from NR-CCE #0, while the CSS corresponding tothe synchronization signal block #1 may be started from NR-CCE #8.

In addition, in an example of the association, the physical channelcarrying the second system information is decoded on the basis ofinformation associated with the physical channel carrying the firstsystem information. Identification information associated with thesynchronization signal block is used as the physical channel carryingthe second system information. Examples of the identificationinformation associated with the synchronization signal block include atime index of the synchronization signal block.

The information associated with the physical channel carrying the firstsystem information in an example is used for scrambling the physicalchannel carrying the second system information. The identificationinformation associated with the synchronization signal block in aspecific example is used for calculation of an initial value cinit of ascramble sequence c. Note that the scrambling is performed by following(Equation 1).

[Math. 1]

b(i)=(a(i)+c(i))mod 2  (Equation 1)

In the above (Equation 1) herein, a(i) indicates an ith bit in a bitstring before the scrambling, b(i) indicates an ith bit in a bit stringafter scrambling, and c(i) indicates an ith bit in a scramble sequence.

The information associated with the physical channel carrying the firstsystem information in an example is used for determination of a CRC maskof the physical channel carrying the second system information. The CRCis scrambled by the CRC mask.

The identification information associated with the synchronizationsignal block in an example is used for determining one CRC mask includedin a plurality of the CRC masks. For example, a correspondence tableindicating correspondence between the identification informationassociated with the synchronization signal block and the CRC mask isdefined. The bit string of the CRC mask is uniquely determined for thepredetermined identification information on the basis of thecorrespondence table. FIG. 17 is a diagram depicting an example of thecorrespondence table indicating correspondence between the time indexand the CRC mask. In the example depicted in FIG. 17 , bit strings ofthe CRC mask are associated with time indexes #0 to #N. The terminalapparatus acquires bit strings of the CRC mask on the basis of values ofthe acquired time index, and the correspondence table indicatingcorrespondence between the value of the time index and the CRC mask.

Note that the CRC mask may be applied to a control channel whichschedules the physical channel carrying the second system information.

In addition, bit strings each having a long distance between codes arepreferably adopted as candidates of the CRC mask.

The identification information associated with the synchronizationsignal block in an example is used for calculation of a value of theSI-RNTI. In a specific example, the SI-RNTI is calculated by acalculation formula of “SI-RNTI=A·time index+C.” In this formula, eachof A and C is a predetermined constant. The terminal apparatusdescrambles the CRC by the CRC mask after conversion of the SI-RNTI intobit strings.

<Details of PRACH of NR in Present Embodiment>

An NR-PRACH includes a Zadoff-Chu sequence or an M-sequence. In theNR-PRACH, a plurality of preamble formats is specified. Each of thepreamble formats is specified by a combination of parameters such as asub carrier interval of the PRACH, a transmission bandwidth, a sequencelength, the number of symbols used for transmission, the transmissionrepeating number, a CP length, and a guard period length. Note that thetype of the sequence used for transmission of the NR-PRACH(Zaddoff-Chu-sequence or M-sequence) may be specified in accordance withthe preamble format.

Settings associated with the NR-PRACH for the terminal apparatus in anidle mode are determined on the basis of the system information.Furthermore, settings associated with the NR-PRACH for the terminalapparatus in a connection mode are determined by dedicated RRCsignaling.

The NR-PRACH is transmitted by a physical resource by which the NR-PRACHis transmittable (NR-PRACH occasion). The physical resource isinstructed in accordance with the settings associated with the NR-PRACH.The terminal apparatus selects any one of the physical resources, andtransmits the NR-PRACH by the selected physical resource. Furthermore,the terminal apparatus in the connection mode transmits the NR-PRACHusing an NR-PRACH resource. The NR-PRACH resource is a combination of anNR-PRACH preamble and the corresponding physical resource. The basestation apparatus is capable of issuing an instruction of the NR-PRACHresource to the terminal apparatus.

The types of the sequences of the preambles of the NR-PRACH arenumbered. Each of the numbers of the types of the sequences of thepreambles is referred to as a preamble index.

The NR-PRACH is retransmitted at the time of a failure of the randomaccess procedure. The terminal apparatus waits for transmission of theNR-PRACH in a standby period calculated from a value of backoff (backoffindicator, BI) at the time of retransmission of NR-PRACH. Note that thevalue of backoff may differ for each terminal category of the terminalapparatus or priority of caused traffic. In this case, a notice of aplurality of the values of backoff is given, and the terminal apparatusselects the value of backoff to be used in accordance with priority. Inaddition, at the time of retransmission of the NR-PRACH, transmissionpower of the NR-PRACH is raised higher than that of initial transmission(this procedure is referred to as power ramping).

<Details of Random Access Response in Present Embodiment>

A random access response of NR is transmitted by an NR-PDSCH.

The NR-PDSCH including a random access response is scheduled by anNR-PDCCH which has CRC scrambled by an RA-RNTI. The NR-PDCCH istransmitted by a common control sub band. The NR-PDCCH is arranged in aCSS (common search space). Note that the value of the RA-RNTI isdetermined on the basis of a transmission resource (time resource (slotor sub frame), and frequency resource (resource block)) of the NR-PRACHcorresponding to the random access response. In addition, the NR-PDCCHmay be arranged in a search space corresponding to the NR-PRACHassociated with the random access response. More specifically, thesearch space where the NR-PDCCH is arranged is set in association withthe preamble of the NR-PRACH and/or the physical resource by which theNR-PRACH is transmitted. The search space where the NR-PDCCH is arrangedis set in association with the preamble index and/or the index of thephysical resource.

The NR-PDCCH corresponds to an NR-SS and QCL.

The random access response of NR corresponds to information associatedwith MAC. The random access response of NR includes at least an uplinkgrant for transmitting the message 3 of NR, a value of a timing advanceused for adjusting frame synchronization of an uplink, and a value of atemporary C-RNTI. In addition, the random access response of NR includesa PRACH index used for NR-PRACH transmission corresponding to the randomaccess response. Furthermore, the random access response of NR includesinformation associated with backoff used for stand-by of transmission ofthe PRACH. The base station apparatus performs transmission includingthese information by using the NR-PDSCH. The terminal apparatusdetermines whether or not the transmission of the random access preamblehas succeeded on the basis of these information. In a case where it isdetermined that the transmission of the random access preamble hassucceeded on the basis of the information, the terminal apparatusperforms a transmission process for transmitting the message 3 of NR inaccordance with the information included in the random access response.On the other hand, in a case where it is determined that thetransmission of the random access preamble has failed, the terminalapparatus considers that the random access procedure has failed, andperforms a retransmission process for retransmitting the NR-PRACH.

Note that the random access response of NR may include a plurality ofuplink grants for transmitting the message 3 of NR. The terminalapparatus may select one resource for transmitting the message 3 fromthe plurality of uplink grants. In this manner, contention oftransmission of the message 3 of NR can be reduced in a case where thedifferent terminal apparatuses receive the same random access responseof NR. Accordingly, more stable random access procedure can be provided.

<Details of Message 3 of NR in Present Embodiment>

The message 3 of NR is transmitted by the NR-PUSCH. The NR-PUSCH istransmitted using a resource instructed by a random access response.

The message 3 of NR includes an RRC connection request message.

Waveform of the NR-PUSCH including the message 3 of NR and transmittedis instructed by a parameter included in the system information. Morespecifically, an OFDM or a DFT-s-OFDM is determined by the instructionof the parameter.

In a case the message 3 of NR is normally received, the base stationapparatus shifts to a transmission process for transmitting contentionresolution. On the other hand, in a case where the message 3 of NR isnot normally received, the base station apparatus is capable of againattempting reception of the message 3 of NR at least for a predeterminedperiod.

In a specific example of a process performed after the message 3 of NRis not normally received, the base station apparatus instructsretransmission of the message 3 to the terminal apparatus. The basestation apparatus transmits an instruction of retransmission of themessage 3 by using a downlink resource a predetermined number of slots(or sub frames, wireless frames) after the resource for whichtransmission of the message 3 has been instructed.

Examples of the retransmission of the message 3 and the instruction ofthe transmission resource include an instruction of retransmission of arandom access response.

The NR-PDSCH including the retransmitted random access responsedescribed above is scheduled by an NR-PDCCH which has CRC scrambled byan RA-RNTI. The value of the RA-RNTI is identical to a value of anRA-RNTI used for initial transmission. More specifically, the value ofthe RA-RNTI is determined on the basis of the transmission resource ofthe NR-PRACH corresponding to the random access response. Alternatively,the value of the RA-RNTI may be determined on the basis of informationfor identifying initial transmission or retransmission as well as thetransmission resource of the NR-PRACH. The NR-PDCCH is arranged in theCSS (common search space).

In addition, the NR-PDSCH including the retransmitted random accessresponse described above is scheduled by a temporary C-RNTI included inthe random access response transmitted by initial transmission, or anNR-PDCCH which has CRC scrambled by a C-RNTI.

Another example of the instruction of the retransmission of the message3 and the transmission resource is an instruction by the NR-PDCCH usedfor the instruction of retransmission of the message 3. The NR-PDCCH isan uplink grant. A resource of retransmission of the message 3 isinstructed by DCI of the NR-PDCCH. The terminal apparatus performsretransmission of the message 3 on the basis of the instruction of theuplink grant.

In a specific example of the process performed after the message 3 of NRis not normally received, the base station apparatus attempts receptionof the message 3 by a retransmission resource instructed beforehand.

In a case where a contention resolution is not transmitted from the basestation apparatus after transmission of the message 3 within apredetermined period, the terminal apparatus transmits the NR-PUSCHincluding the message 3 using the retransmission resource instructedbeforehand.

In addition, in a case where NACK for the message 3 is received, theterminal apparatus may transmit the NR-PUSCH including the message 3using the retransmission resource instructed beforehand andcorresponding to the NACK.

For example, the retransmission resource instructed beforehand isincluded in the system information or the random access response.

Note that in a case where the number of times of retransmission of themessage 3 of NR exceeds a predetermined number, or in a case wherereception of the contention resolution of NR does not succeed within apredetermined period, the terminal apparatus considers that the randomaccess procedure has failed, and performs a retransmission process forretransmitting the NR-PRACH.

In addition, a transmission beam of the terminal apparatus used forretransmission of the message 3 of NR may be different from atransmission beam of the terminal apparatus used for initialtransmission of the message 3.

In addition, in a case where neither the contention resolution of NR northe instruction of retransmission of the message 3 is received withinthe predetermined period, the terminal apparatus considers that therandom access procedure has failed, and performs the retransmissionprocess of the NR-PRACH. For example, the predetermined period is set inaccordance with the system information.

<Details of Contention Resolution of NR in Present Embodiment>

A contention resolution of NR is transmitted by an NR-PDSCH. TheNR-PDSCH including the contention resolution is scheduled by an NR-PDCCHwhich has CRC scrambled by a temporary C-RNTI or a C-RNTI. The NR-PDCCHis transmitted in a common control sub band. The NR-PDCCH is arranged ina USS (terminal specific search space). Note that the NR-PDCCH may bearranged in a CSS.

In a case where the NR-PDSCH including the contention resolution isnormally received, the terminal apparatus issues a response of ACK tothe base station apparatus. Thereafter, the random access procedure isconsidered to have succeeded, and the terminal apparatus comes into theconnection state. On the other hand, in a case where NACK correspondingto the NR-PDSCH including the contention resolution is received from theterminal apparatus, or in a case of no response, the base stationapparatus retransmits the NR-PDSCH including the contention resolution.Furthermore, in a case where the contention resolution of NR is notreceived within a predetermined period, the terminal apparatus considersthat the random access procedure has failed, and performs aretransmission process for retransmitting an NR-PRACH.

<Initial Beam Selection of NR in Present Embodiment>

The terminal apparatus selects a beam provided from the base stationapparatus also in initial connection of NR.

The base station apparatus is capable of transmitting a beam differentfor each synchronization signal block.

FIG. 18 is a diagram depicting an example of a communication sequencefor initial beam selection in NR. As depicted in FIG. 18 , the basestation apparatus initially transmits N synchronization signal blocks(S201). The terminal apparatus measures N pieces of reception power(RSRP) and/or a signal to interference ratio (e.g., RSRQ or SINR) usingan NR-SS transmitted by the corresponding synchronization signal block,and selects one synchronization signal block suited for connection(S203). Subsequently, the terminal apparatus determines a PRACH indexand a PRACH resource corresponding to the selected synchronizationsignal block on the basis of RACH setting included in the systeminformation (S205), and transmits the PRACH to the base stationapparatus (S207). The base station apparatus is capable of acquiring thesynchronization signal block number more suitable for the terminalapparatus in accordance with the received PRACH on the basis of arelationship between the index of the PRACH corresponding to theselected synchronization signal block and the PRACH resource. In otherwords, the base station apparatus is capable of recognizing a downlinkbeam more suitable for the terminal apparatus on the basis of thecommunication sequence depicted in FIG. 18 , and is capable of applyingthe downlink beam to following downlink communication (S209).

<Beam Management Method for Initial Access of NR in Present Embodiment>

Described next will be an example of a method for beam managementaccording to the present disclosure, focusing on beam management at aninitial access of NR.

In the wireless communication system according to the presentembodiment, the terminal apparatus again measures quality of beams, andfeeds back information associated with a beam having preferable linkquality (e.g., preferable beam other than initial beam) to the basestation apparatus in addition to selection of the initial beam describedwith reference to FIG. 18 . More specifically, the terminal apparatusadds information associated with a downlink beam (i.e., informationassociated with the foregoing beam having preferable link quality) to anuplink channel, for example, to feed back the information to the basestation apparatus.

In a specific example, during an initial access, the terminal apparatusis only required to insert information associated with the downlink beaminto a message (e.g., message 3) transmitted to the base stationapparatus after reception of a random access response in the randomaccess procedure, and feed back the message to the base stationapparatus. More specifically, the terminal apparatus may use the message1 for feedback of information associated with the best beam, and may usethe message 3 for feedback of information associated with the best beam,or the second best beam next to the best beam.

Note that the terminal apparatus is allowed to feed back informationassociated with only one beam at the time of feedback of informationassociated with a preferable beam using the PRACH, such as the time ofselection of the initial beam described with reference to FIG. 18 . Onthe other hand, in the case of feedback using the message 3 during therandom access procedure, the terminal apparatus is allowed to feed backinformation associated with a plurality of beams as well as one beam.

In addition, the base station apparatus at this time may provide asharper beam than the beam provided during selection of the initial beam(i.e., signal so controlled as to have higher directivity). The wirelesscommunication system of the present embodiment performing such controlis capable of providing a higher quality link between the base stationapparatus and the terminal apparatus.

For example, FIG. 19 is a diagram depicting an example of types of beamduring beam refinement. In the example depicted in FIG. 19 , respectiverobes of beams of a synchronization signal block (beams indicated by abroken line in the figure), and beams of CSI-RS (beams indicated bysolid lines in the figure). More specifically, in the example depictedin FIG. 19 , the terminal apparatus selects a looser beam (i.e., beamhaving lower directivity) for the purpose of reduction of the connectiontime during the initial connection. Subsequently, the terminal apparatusselects a sharper beam (i.e., beam having higher directivity) on thebasis of the looser beam after selection of the looser beam andestablishment of an access to the base station apparatus. The procedurefor accessing with a sharper beam on the basis of a looser beam in thismanner is also referred to as “beam refinement.”

By performing the control described above, the base station apparatus iscapable of acquiring information associated with a plurality of beamsfrom the terminal apparatus. In addition, by performing the controldescribed above, the base station apparatus is capable of using aplurality of beams for downlink transmission of the message 4 and thefollowing messages in the random access procedure. Accordingly, thewireless communication system of the present embodiment is capable ofsecuring robustness for propagation losses produced by shieldingwireless signals or the like in comparison with a case of use of onlyone beam. More specifically, the base station apparatus is capable ofcontinuing communication with the terminal apparatus by using the secondbest beam even under an environment where losses are produced byshielding of the best beam by any shield.

In addition, a plurality of beams is allowed to be used in the message 4and the following messages in the random access procedure. Accordingly,the procedure of the initial access can be completed more stably andrapidly in comparison with the case of use of only one beam.Particularly at the procedure of the initial access, a probability offailure of the procedure of the initial access increases in a case wherea stable beam is difficult to provide. In addition, in a case of failureof the procedure of the initial access, the corresponding procedure maybe required to be repeated from the beginning. Particularly, when thenumber of the terminal apparatuses attempting execution of the procedureincreases, a contention probability of respective signals and channelsin the RACH procedure increases. Accordingly, completion of theprocedure may become more difficult to achieve. Even in this case, thewireless communication system of the present embodiment is capable ofmore stably and more rapidly completing the procedure of the initialaccess.

(Beam Management Method 1: Method Using Synchronization Signal Block)

Next, a method using a synchronization signal block as an example of themethod of beam management will be hereinafter described.

The base station apparatus is capable of giving a notice of informationassociated with a synchronization signal block to the terminal apparatusin accordance with the system information. Examples of the informationassociated with the synchronization signal block include informationassociated with a synchronization signal block actually transmitted, andinformation associated with a beam used for transmission of thesynchronization signal block. Note that transmission of nosynchronization signal block is allowed. Information indicating thisstate may be inserted into the information associated with thesynchronization signal block. In other words, for example, theinformation associated with the synchronization signal block may includeinformation indicating the synchronization signal block actuallytransmitted by the base station apparatus in synchronization signalblocks allowed to be transmitted, for example.

Examples of the information fed back to the base station apparatus fromthe terminal apparatus include an index identifying the synchronizationsignal block, and information associated with the time of transmissionof the synchronization signal block (e.g., information indicating a subframe, a slot, and a symbol). For example, indexes corresponding to allsynchronization signal blocks likely to be transmitted may be fed backfrom the terminal apparatus to the base station apparatus as indexes foridentifying the synchronization signal blocks. In addition, in anotherexample, an index corresponding to the synchronization signal blockactually transmitted may be fed back from the terminal apparatus to thebase station apparatus.

Furthermore, the terminal apparatus may feed back additional informationas well as the information for identifying the synchronization signalblock (e.g., index) to the base station apparatus. Examples of theadditional information include a measurement result of reception power(RSRP) of the signal block for which the information is fed back. Inaddition, the terminal apparatus may feed back to the base stationapparatus, as the additional information, a comparison result ofpredetermined information between the initial beam and the beamcorresponding to the synchronization signal block for which informationis fed back. In a specific example, the terminal apparatus may feed backto the base station apparatus, as the additional information,information indicating whether or not channel quality of the beamcorresponding to the target synchronization signal block is higher thanchannel quality of the initial beam. In addition, in another example,the terminal apparatus may feed back to the base station apparatus, asthe additional information, information associated with a difference inthe reception power between the beam corresponding to the targetsynchronization signal block and the initial beam. Note that a referencesignal corresponding to a measurement target at the time ofdetermination of the initial beam (e.g., NR-SS included in thesynchronization signal block) corresponds to an example of a “firstreference signal.” In addition, a reference signal corresponding to atarget of measurement at the time of feedback of the information, i.e.,the reference signal corresponding to a measurement target after arandom access response corresponds to an example of a “second referencesignal.”

Furthermore, the terminal apparatus may also feed back informationassociated with a synchronization signal block transmitted from aneighbor cell to the base station apparatus. In this case, note that theterminal apparatus may give a notice of information for identifying theneighbor cell (e.g., cell ID) to the base station apparatus.

An example of a communication sequence in beam management using asynchronization signal block will be herein described with reference toFIG. 20 . FIG. 20 is a diagram depicting an example of a communicationsequence in the beam management according to the present embodiment,presenting an example of a method using a synchronization signal block.As depicted in FIG. 20 , the base station apparatus initially transmitsN synchronization signal blocks (S221). The terminal apparatus measuresN pieces of reception power (RSRP) and/or a signal to interference ratio(e.g., RSRQ or SINR) using an NR-SS transmitted by the correspondingsynchronization signal block, and selects one or more synchronizationsignal blocks suited for connection (S223). At this time, the terminalapparatus may select a plurality of synchronization signal blocks. Notethat a configuration of a part selecting the synchronization signalblock in the terminal apparatus corresponds to an example of a“selection unit,” and may correspond to the control unit 203 depicted inFIG. 6 , for example. Subsequently, the terminal apparatus insertsinformation corresponding to the one or more selected synchronizationsignal blocks into the message 3 in the random access procedure (S225),and transmits the message 3 to the base station apparatus (S227). Thebase station apparatus is capable of acquiring one or moresynchronization signal block numbers more suited for the terminalapparatus (and antenna information associated with transmission of thesynchronization signal block) from the received message 3 on the basisof the information corresponding to the selected synchronization signalblock. In other words, by the communication sequence depicted in FIG. 20, the base station apparatus is capable of recognizing one or moredownlink beams more suited for the terminal apparatus, and is capable ofapplying the one or more downlink beams to following downlinkcommunication (S229). Note that a configuration of a part included inthe terminal apparatus and transmitting the message 3 to the basestation apparatus corresponds to an example of a “notice unit,” and maycorrespond to the transmission unit 207 depicted in FIG. 6 , forexample. In addition, a configuration of a part included in the basestation apparatus and receiving the message 3 from the terminalapparatus (in other words, configuration acquiring the synchronizationsignal block number from the message 3) corresponds to an example of an“acquisition unit,” and may correspond to the reception unit 105depicted in FIG. 5 , for example.

(Beam Management Method 2: Method Using Aperiodic CSI-RS)

Next, a method using an aperiodic CSI-RS will be hereinafter describedas an example of the beam management method.

Aperiodic CSI-RS transmission will be initially described. The aperiodicCSI-RS transmission represents transmission of a CSI-RS once or aplurality of times by any trigger. Note that the aperiodic CSI-RStransmission requires CSI-RS setting and a trigger of the CSI-RStransmission.

A setting method of the aperiodic CSI-RS will be described. The basestation apparatus gives a notice of setting of the aperiodic CSI-RS tothe terminal apparatus in accordance with the system information. Atthis time, the setting of the aperiodic CSI-RS is transmitted in thesecond system information. In addition, examples of the setting of theaperiodic CSI-RS include information associated with timing, a cell ID,a QCL parameter, information associated with a sequence of the CSI-RS,information associated with the number of antenna ports and RE mapping,and numerology of the CSI-RS (sub carrier interval). For example, thetiming is represented by a cycle and an offset. For example, theinformation associated with the QCL parameter may include informationindicating a synchronization signal block establishing QCL(Quasi-Co-Location). In addition, for example, the informationassociated with the QCL parameter may include information indicating aPDCCH-DMRS establishing QCL. The information associated with thesequence of the CSI-RS may include information associated with asequence type. In addition, the information associated with the sequenceof the CSI-RS may include information associated with an initial valueof the sequence. Furthermore, for example, mapping candidates may bedetermined beforehand, and indexes associated with the candidates may begiven as a notice of information associated with the RE mapping.

In addition, all the terminal apparatuses within a cell each recognize alocation where the CSI-RS is mapped in accordance with setting of theaperiodic CSI-RS regardless of whether or not the aperiodic CSI-RS isactually transmitted. Furthermore, the terminal apparatus performsdemodulation and decoding assuming that a PDSCH is not arranged in REwhere the CSI-RS is arranged.

Next described will be an operation associated with transmission of theaperiodic CSI-RS (particularly a relationship between a trigger andtransmission). For example, the aperiodic CSI-RS is transmitted inassociation with a random access response in the random accessprocedure.

In a specific example, the CSI-RS may be transmitted at the sametransmission timing as that of the random access response. In this case,the CSI-RS is transmitted in a slot identical to the slot fortransmission of the random access response. In addition, in a case whereschedule information associated with the random access response isacquired, the terminal apparatus receives the CSI-RS in a slot for whicha random access response is scheduled.

Furthermore, in another example, the CSI-RS may be transmitted at timingafter the random access response. In this case, the terminal apparatusrecognizes the transmission timing of the CSI-RS on the basis ofinformation included in the random access response. Examples of theinformation included in the random access response include a slot index.In this case, the CSI-RS is transmitted in a slot corresponding to theslot index. In addition, in a further example, the information includedin the random access response may be information indicating a relativetime between a slot for transmission of the random access response and aslot for transmission of the CSI-RS. In this case, the CSI-RS istransmitted in a slot transmitted after an elapse of a period indicatedby the relative time from transmission of the random access response.

In addition, for example, the information associated with the CSI-RSsetting such as the transmission timing described above may betransmitted while inserted into DCI scheduling a PDSCH including therandom access response. Furthermore, in a further example, theinformation associated with the CSI-RS setting may be transmitted whileinserted into the random access response.

Moreover, in a further example, the terminal apparatus may recognize thetransmission timing of the CSI-RS on the basis of information includedin setting of the aperiodic CSI-RS, and the random access response. In aspecific example, the setting of the aperiodic CSI-RS may includeinformation associated with the time at which the CSI-RS is likely to betransmitted (e.g., cycle and offset). In this case, for example, in acase where the random access response is received, the CSI-RS may betransmitted in a slot which is located after the slot of the receivedrandom access response, and is likely to be used for transmission of thelatest CSI-RS.

Described herein with reference to FIG. 21 will be an example of acommunication sequence of beam management using the CSI-RS. FIG. 21 is adiagram depicting an example of the communication sequence of the beammanagement according to the present embodiment, presenting an example ofa method using the CSI-RS. As depicted in FIG. 21 , the base stationapparatus initially transmits N pieces of the CSI-RS (S241). Theterminal apparatus measures reception power (RSRP) and/or a signal tointerference ratio (e.g., RSRQ or SINR) of each of the N pieces of theSCI-RS, and selects one or more pieces of the CSI-RS suited forconnection (S243). At this time, the terminal apparatus may select aplurality of pieces of the CSI-RS. Subsequently, the terminal apparatusinserts information corresponding to the selected one or more pieces ofCSI-RS into the message 3 in the random access procedure (S245), andtransmits the message 3 to the base station apparatus (S247). The basestation apparatus is capable of acquiring one or more CSI-RS numbersmore suited for the terminal apparatus (and antenna informationassociated with transmission of the CSI-RS) on the basis of theinformation included in the received message 3 (i.e., informationcorresponding to the selected CSI-RS). In other words, on the basis ofthe communication sequence depicted in FIG. 21 , the base stationapparatus is capable of recognizing one or more downlink beams moresuited for the terminal apparatus, and is capable of applying the one ormore downlink beams to following downlink communication (S249).

Note that both the beam management method 1 and the beam managementmethod 2 described above may be executed. In this case, for example, theterminal apparatus may feed back information associated with a pluralityof rough beams to the base station apparatus by using the beammanagement method 1, and feed back information associated with a finebeam by using the beam management method 2.

(Operation after Feedback of Information Associated with BeamManagement)

Subsequently, an example of operations of the terminal apparatus and thebase station apparatus after feedback of information associated withbeam management from the terminal apparatus to the base stationapparatus will be hereinafter described. Note that the beamcorresponding to the information fed back from the terminal apparatus tothe base station apparatus by the PRACH in the present explanation isalso referred to as a “first beam” for convenience as described withreference to FIG. 18 . More specifically, the first beam corresponds toone beam determined in accordance with information fed back from theterminal apparatus before a random access response in the random accessprocedure. In addition, at least in either the beam management method 1or the beam management method 2 described with reference to FIGS. 20 and21 , the beam corresponding to the information fed back from theterminal apparatus to the base station apparatus by the message to betransmitted after the random access response such as the message 3 isalso referred to as a “second beam” for convenience. More specifically,the second beam corresponds to one or more beams determined inaccordance with information fed back from the terminal apparatus afterthe random access response. Note that a reference signal associated withthe second beam is the NR-SS included in the synchronization signalblock in the case of the beam management method 1, and is the CSI-RS inthe case of the beam management method 2 as described above. Inaddition, antenna information corresponding to the first beamcorresponds to “first antenna information,” while antenna informationcorresponding to the second beam corresponds to “second antennainformation.”

In the wireless communication system according to the presentembodiment, the terminal apparatus monitors a corresponding NR-PDCCHassuming QCL conditions of the first beam and the second beam describedabove, and performs reception and demodulation of the NR-PDCCH. Inaddition, the base station apparatus transmits a DMRS of the NR-PDCCH,and a reference signal associated with the first beam information fromthe same transmission point.

An example of an operation for switching QCL will be hereinafterdescribed.

For example, as in the beam management method 1 and the beam managementmethod 2 described above, QCL may be switched after beam managementperformed after reception of the random access response (in other words,feedback from the terminal apparatus to the base station apparatus usingthe message 3). In this case, for example, the DMRS of the NR-PDCCH andthe reference signal associated with the first beam information mayestablish QCL before execution of the beam management. In addition, theDMRS of the NR-PDCCH and the reference signal associated with the secondbeam information may establish QCL after execution of the beammanagement. In other words, communication is controlled on the basis ofthe first antenna information corresponding to the first beam beforeexecution of the beam management, and communication is controlled on thebasis of the second antenna information corresponding to the second beamafter execution of the beam management.

In addition, in another example, QCL may be switched between initialtransmission and retransmission in a case where retransmission isperformed in the communication between the base station apparatus andthe terminal apparatus. In a specific example where transmission of thePDSCH including the message 4 is initial transmission, the DMRS of theNR-PDCCH and the reference signal associated with the first beaminformation may establish QCL. In addition, in a case where transmissionof the PDSCH including the message 4 is retransmission, the DMRS of theNR-PDCCH and the reference signal associated with the second beaminformation may establish QCL. In other words, in the transmission ofthe PDSCH including the message 4, communication is controlled on thebasis of the first antenna information corresponding to the first beamin the case of first transmission, while communication is controlled onthe basis of the second antenna information corresponding to the secondbeam in the case of retransmission.

In addition, in a further example, QCL may be switched in accordancewith a search space where the DMRS of the NR-PDCCH is arranged. Forexample, in a first search space and a second search space differentfrom each other, the DMRS of the NR-PDCCH arranged in the first searchspace and the reference signal associated with the first beaminformation may establish QCL. In addition, the DMRS of the NR-PDCCHarranged in the second search space and the reference signal associatedwith the second beam information may establish QCL. In a more specificexample, the DMRS of the NR-PDCCH arranged in a CSS and the referencesignal associated with the first beam information may establish QCL. Inaddition, the DMRS of NR-PDCCH arranged in an USS and the referencesignal associated with the second beam information may establish QCL. Inother words, in a case where transmission data is transmitted via aphysical channel belonging to the first search space, communication maybe controlled on the basis of the first antenna informationcorresponding to the first beam. In addition, in a case wheretransmission data is transmitted via a physical channel belonging to thesecond search space, communication may be controlled on the basis of thesecond antenna information corresponding to the second beam.

In addition, in a further example, QCL may be switched in accordancewith a symbol for transmission of the DMRS of the NR-PDCCH. For example,concerning a first OFDM symbol and a second OFDM symbol different fromeach other, the DMRS of the NR-PDCCH transmitted by the first OFDMsymbol and the reference signal associated with the first beaminformation may establish QCL. In addition, the DMRS of the NR-PDCCHtransmitted by the second OFDM symbol and the reference signalassociated with the second beam information may establish QCL. In otherwords, in a case where a signal is transmitted by the first OFDM symbol,communication may be controlled on the basis of the first antennainformation corresponding to the first beam. In addition, in a casewhere a signal is transmitted by the second OFDM symbol, communicationmay be controlled on the basis of the second antenna informationcorresponding to the second beam. Note that the first OFDM symbolcorresponds to an example of a “first symbol,” while the second OFDMsymbol corresponds to an example of a “second symbol.”

In addition, in a further example, QCL may be switched in accordancewith information included in the NR-PDCCH referred to as a common PDCCH.For example, in a case of a notice indicating QCL with the referencesignal associated with the first beam information on the basis of theinformation included in the NR-PDCCH, a DMRS of another NR-PDCCH and thereference signal associated with the first beam information mayestablish QCL. In addition, in a case of a notice indicating QCL withthe reference signal associated with the second beam information on thebasis of the information included in the NR-PDCCH, a DMRS of anotherNR-PDCCH and the reference signal associated with the second beaminformation may establish QCL.

The example of the operation associated with switching of QCL has beendescribed above as an operation performed after feedback of informationassociated with beam management. Note that, while transmission of theDMRS of the NR-PDCCH has been focused on in the above description, abehavior similar to the behavior described above may be applied to aDMRS of an NR-PDSCH.

2. Application Examples

The technology according to the present disclosure is applicable tovarious products. For example, the base station apparatus 1 may beimplemented as an eNB (evolved Node B) of any type, such as a macro eNBor a small eNB. The small eNB may be an eNB covering a smaller cell thana macro cell, such as a pico-eNB, a micro-eNB, and a home (femto)-eNB.Alternatively, the base station apparatus 1 may be implemented as a basestation of other types, such as an NodeB and a BTS (Base TransceiverStation). The base station apparatus 1 may include a main body forcontrolling wireless communication (also referred to as base stationapparatus), and one or more RRHs (Remote Radio Heads) disposed at aplace different from the place of the main body. In addition, a terminalof various types described below may temporarily or semi-permanentlyexecute a base station function to operate as the base station apparatus1. Furthermore, at least a part of components of the base stationapparatus 1 may be implemented in a base station apparatus or a modulefor a base station apparatus.

In addition, for example, the terminal apparatus 2 may be implemented asa smartphone, a tablet PC (Personal Computer), a note PC, a portablegame terminal, a portable/dongle mobile router or a mobile terminal suchas a digital camera, and an in-vehicle terminal such as a car navigationapparatus. Moreover, the terminal apparatus 2 may be implemented as aterminal performing M2M (Machine To Machine) communication (alsoreferred to as MTC (Machine Type Communication)). Furthermore, at leasta part of components of the terminal apparatus 2 may be implemented in amodule mounted on these terminals (e.g., an integrated circuit moduleconstituted by one die).

<2.1. Application Example of Base Station>

First Application Example

FIG. 22 is a block diagram depicting a first example of a schematicconfiguration of an eNB to which the technology of the presentdisclosure is applicable. An eNB 800 includes one or more antennas 810,and a base station apparatus 820. The respective antennas 810 and thebase station apparatus 820 may be connected to each other via an RFcable.

Each of the antennas 810 includes a single or a plurality of antennaelements (e.g., a plurality of antenna elements constituting a MIMOantenna), and is used for transmission and reception of wireless signalsgenerated by the base station apparatus 820. The eNB 800 may include theplurality of antennas 810 as depicted in FIG. 22 , and the plurality ofantennas 810 may correspond to a plurality of frequency bands used bythe eNB 800, for example. Note that, while FIG. 22 depicts an example ofthe eNB 800 which includes the plurality of antennas 810, the eNB 800may have the single antenna 810.

The base station apparatus 820 includes a controller 821, a memory 822,a network interface 823, and a wireless communication interface 825.

The controller 821 may be a CPU or a DSP, for example, and allowsoperations of various functions of an upper layer of the base stationapparatus 820. For example, the controller 821 generates a data packetfrom data in a signal processed by the wireless communication interface825, and transfers the generated packet via the network interface 823.The controller 821 may generate a bundled packet by bundling datareceived from a plurality of baseband processors, and transfer thegenerated bundled packet. In addition, the controller 821 may have alogical function for executing controls such as radio resource control,radio bearer control, mobility management, admission control, andscheduling. In addition, these controls may be executed in cooperationwith a peripheral eNB or a core network node. The memory 822 includes aRAM or a ROM, and stores programs executed by the controller 821, andvarious types of control data (e.g., terminal list, transmission powerdata, and scheduling data).

The network interface 823 is a communication interface for connectingthe base station apparatus 820 to the core network 824. The controller821 may communicate with a core network node or another eNB via thenetwork interface 823. In this case, the eNB 800 and the core networknode or the other eNB may be connected to each other via a logicalinterface (e.g., S1 interface or X2 interface). The network interface823 may be a wired communication interface, or a wireless communicationinterface for wireless backhaul. In a case where the network interface823 is a wireless communication interface, the network interface 823 mayuse, for wireless communication, a frequency band higher than thefrequency band used by the wireless communication interface 825.

The wireless communication interface 825 supports any cellularcommunication method such as LTE (Long Term Evolution) and LTE-Advanced,and provides wireless connection for a terminal positioned in a cell ofthe eNB 800 via the antenna 810. The wireless communication interface825 may typically include a baseband (BB) processor 826, an RF circuit827 and the like. For example, the BB processor 826 may performencoding/decoding, modulation/demodulation, multiplexing/demultiplexingand the like, and executes various signal processes for respectivelayers (e.g., L1, MAC (Medium Access Control), RLC (Radio Link Control),and PDCP (Packet Data Convergence Protocol)). The BB processor 826 mayhave a part of all of the logical functions described above in place ofthe controller 821. The BB processor 826 may be a module including amemory storing a communication control program, a processor forexecuting the program, and an associated circuit. The function of the BBprocessor 826 may be changed by update of the program. In addition, themodule may be a card or a blade inserted into a slot of the base stationapparatus 820, or may be a chip mounted on the card or the blade. On theother hand, the RF circuit 827 may include a mixer, a filter, anamplifier and the like, and transmits and receives wireless signals viathe antenna 810.

As depicted in FIG. 22 , the wireless communication interface 825 mayinclude a plurality of the BB processors 826, and the plurality of BBprocessors 826 may correspond to a plurality of frequency band rangesused by the eNB 800, for example. In addition, as depicted in FIG. 22 ,the wireless communication interface 825 may include a plurality of theRF circuits 827, and the plurality of RF circuits 827 may correspond toa plurality of antenna elements, for example. Note that, while FIG. 22depicts the example of the wireless communication interface 825 whichincludes the plurality of BB processors 826 and the plurality of RFcircuits 827, the wireless communication interface 825 may include thesingle BB processor 826 and the single RF circuit 827.

In the eNB 800 depicted in FIG. 22 , one or more components of the upperlayer processing unit 101 and the control unit 103 described withreference to FIG. 5 may be mounted on the wireless communicationinterface 825. Alternatively, at least a part of these components may bemounted on the controller 821. In an example, a part (e.g., BB processor826) or all of the wireless communication interface 825, and/or modulesincluding the controller 821 may be mounted on the eNB 800, and the oneor more components described above may be mounted on the module. In thiscase, the module may store a program under which the processor functionsas the one or more components described above (i.e., program under whichthe processor executes operations of the one or more componentsdescribed above), and execute the program. In another example, a programunder which the processor functions as the one or more componentsdescribed above may be installed in the eNB 800, and the wirelesscommunication interface 825 (e.g., BB processor 826) and/or thecontroller 821 may execute the program. In this manner, the eNB 800, thebase station apparatus 820, or the module may be provided as anapparatus including the one or more components described above, or theprogram under which the processor functions as the one or morecomponents described above may be provided. In addition, a readablerecording medium in which the program is recorded may be provided.

In addition, in the eNB 800 depicted in FIG. 22 , the reception unit 105and the transmission unit 107 described with reference to FIG. 5 may bemounted on the wireless communication interface 825 (e.g., RF circuit827). Moreover, the transmission and reception antenna 109 may bemounted on the antenna 810. Furthermore, the network communication unit130 may be mounted on the controller 821 and/or the network interface823.

Second Application Example

FIG. 23 is a block diagram depicting a second example of the schematicconfiguration of the eNB to which the technology of the presentdisclosure is applicable. An eNB 830 includes one or more antennas 840,a base station apparatus 850, and an RRH 860. The respective antennas840 and the RRH 860 may be connected to each other via an RF cable. Inaddition, the base station apparatus 850 and the RRH 860 may beconnected to each other via a high-speed line such as an optical fibercable.

Each of the antennas 840 includes a single or a plurality of antennaelements (e.g., a plurality of antenna elements constituting a MIMOantenna), and is used for transmission and reception of wireless signalsgenerated by the RRH 860. The eNB 830 may include the plurality ofantennas 840 as depicted in FIG. 23 , and the plurality of antennas 840may correspond to a plurality of frequency bands used by the eNB 830,for example. Note that, while FIG. 23 depicts an example of the eNB 830which includes the plurality of antennas 840, the eNB 830 may have thesingle antenna 840.

The base station apparatus 850 includes a controller 851, a memory 852,a network interface 853, a wireless communication interface 855, and aconnection interface 857. The controller 851, the memory 852, and thenetwork interface 853 are similar to the controller 821, the memory 822,and the network interface 823 described with reference to FIG. 22 .

The wireless communication interface 855 supports any cellularcommunication method such as LTE and LTE-Advanced, and provides wirelessconnection for a terminal positioned in a sector corresponding to theRRH 860 via the RRH 860 and the antenna 840. The wireless communicationinterface 855 may typically include a BB processor 856 and the like. TheBB processor 856 is similar to the BB processor 826 described withreference to FIG. 22 except that the BB processor 856 is connected tothe RF circuit 864 of the RRH 860 via the connection interface 857. Asdepicted in FIG. 22 , the wireless communication interface 855 mayinclude a plurality of the BB processors 856, and the plurality of BBprocessors 856 may correspond to a plurality of frequency band rangesused by the eNB 830, for example. Note that, while FIG. 23 depicts theexample of the wireless communication interface 855 which includes theplurality of BB processors 856, the wireless communication interface 855may include the single BB processor 856.

The connection interface 857 is an interface for connecting the basestation apparatus 850 (wireless communication interface 855) to the RRH860. The connection interface 857 may be a communication module whichconnects the base station apparatus 850 (wireless communicationinterface 855) and the RRH 860 for communication via the high-speedcircuit described above.

In addition, the RRH 860 includes a connection interface 861 and awireless communication interface 863.

The connection interface 861 is an interface for connecting the RRH 860(wireless communication interface 863) to the base station apparatus850. The connection interface 861 may be a communication module forcommunication by the high-speed circuit described above.

The wireless communication interface 863 transmits and receives wirelesssignals via the antennas 840. The wireless communication interface 863may typically include an RF circuit 864 and the like. The RF circuit 864may include a mixer, a filter, an amplifier and the like, and transmitsand receives wireless signals via the antenna 840. As depicted in FIG.23 , the wireless communication interface 863 may include a plurality ofthe RF circuits 864, and the plurality of RF circuits 864 may correspondto a plurality of antenna elements, for example. Note that, while FIG.23 depicts the example of the wireless communication interface 863 whichincludes the plurality of RF circuits 864, the wireless communicationinterface 863 may include the single RF circuit 864.

In the eNB 830 depicted in FIG. 23 , one or more components of the upperlayer processing unit 101 and the control unit 103 described withreference to FIG. 5 may be mounted on the wireless communicationinterface 855 and/or the wireless communication interface 863.Alternatively, at least a part of these components may be mounted on thecontroller 851. In an example, a module including a part (e.g., BBprocessor 856) or all of the wireless communication interface 855,and/or the controller 851 may be mounted on the eNB 830. The one or morecomponents described above may be mounted on the module. In this case,the module may store a program under which the processor functions asthe one or more components described above (i.e., program under whichthe processor executes operations of the one or more componentsdescribed above), and execute the program. In another example, a programunder which the processor functions as the one or more componentsdescribed above may be installed in the eNB 830, and the wirelesscommunication interface 855 (e.g., BB processor 856) and/or thecontroller 851 may execute the program. In this manner, the eNB 830, thebase station apparatus 850, or the module may be provided as anapparatus including the one or more components described above, or theprogram under which the processor functions as the one or morecomponents described above may be provided. In addition, a readablerecording medium in which the program is recorded may be provided.

In addition, in the eNB 830 depicted in FIG. 23 , the reception unit 105and the transmission unit 107 described with reference to FIG. 5 may bemounted on the wireless communication interface 863 (e.g., RF circuit864), for example. Moreover, the transmission and reception antenna 109may be mounted on the antenna 840. Furthermore, the networkcommunication unit 130 may be mounted on the controller 851 and/or thenetwork interface 853.

<2.2. Application Example of Terminal Apparatus>

First Application Example

FIG. 24 is a block diagram depicting an example of a schematicconfiguration of a smartphone 900 to which the technology of the presentdisclosure is applicable. The smartphone 900 includes a processor 901, amemory 902, a storage 903, an external connection interface 904, acamera 906, a sensor 907, a microphone 908, an input device 909, adisplay device 910, a speaker 911, a wireless communication interface912, one or more antenna switches 915, one or more antennas 916, a bus917, a battery 918, and auxiliary controller 919.

The processor 901 may be a CPU or a SoC (System on Chip), for example,and controls functions of an application layer and other layers of thesmartphone 900. The memory 902 includes a RAM and a ROM, and storesprograms executed by the processor 901 and data. The storage 903 mayinclude a storage medium such as a semiconductor memory and a hard disk.The external connection interface 904 is an interface for connecting anexternal device such as a memory card and a USB (Universal Serial Bus)device to the smartphone 900.

For example, the camera 906 includes an imaging device such as a CCD(Charge Coupled Device) and a CMOS (Complementary Metal OxideSemiconductor), and generates a captured image. For example, the sensor907 may include sensors such as a positioning sensor, a gyro sensor, ageomagnetic sensor, and an acceleration sensor. The microphone 908converts voices input to the smartphone 900 into audio signals. Forexample, the input device 909 includes a touch sensor for detecting atouch on a screen of the display device 910, a keypad, a keyboard,buttons or switches, and others, and receives an operation or aninformation input from a user. The display device 910 has a screen suchas a liquid crystal display (LCD) and an organic light emitting diode(OLED) display, and displays an output image of the smartphone 900. Thespeaker 911 converts audio signals output from the smartphone 900 intovoices.

The wireless communication interface 912 supports any cellularcommunication method such as LTE and LTE-Advanced, and executes wirelesscommunication. The wireless communication interface 912 may typicallyinclude a BB processor 913, an RF circuit 914 and the like. For example,the BB processor 913 may perform encoding/decoding,modulation/demodulation, multiplexing/demultiplexing and the like, andexecutes various signal processes for wireless communication. On theother hand, the RF circuit 914 may include a mixer, a filter, anamplifier and the like, and transmits and receives wireless signals viathe antenna 916. The wireless communication interface 912 may be aone-chip module which integrates the BB processor 913 and the RF circuit914. As depicted in FIG. 24 , the wireless communication interface 912may include a plurality of the BB processors 913 and a plurality of theRF circuits 914. Note that, while FIG. 24 depicts the example of thewireless communication interface 912 which includes the plurality of BBprocessors 913 and the plurality of RF circuits 914, the wirelesscommunication interface 912 may include the single BB processor 913 andthe single RF circuit 914.

In addition, the wireless communication interface 912 may support othertypes of wireless communication method such as a near fieldcommunication method, a proximity wireless communication method, and awireless LAN (Local Area Network) method as well as the cellularcommunication method. In this case, the wireless communication interface912 may include the BB processor 913 and the RF circuit 914 for each ofthe wireless communication methods.

Each of the antenna switches 915 switches a connection destination ofthe antenna 916 between a plurality of circuits included in the wirelesscommunication interface 912 (e.g., circuits for different wirelesscommunication methods).

Each of the antennas 916 includes a single or a plurality of antennaelements (e.g., a plurality of antenna elements constituting a MIMOantenna), and is used for transmission and reception of wireless signalsthrough the wireless communication interface 912. As depicted in FIG. 24, the smartphone 900 may include a plurality of the antennas 916. Notethat, while FIG. 24 depicts an example of the smartphone 900 whichincludes the plurality of antennas 916, the smartphone 900 may have thesingle antenna 916.

In addition, the smartphone 900 may include the antenna 916 for each ofthe wireless communication methods. In this case, the antenna switch 915may be eliminated from the configuration of the smartphone 900.

The bus 917 connects the processor 901, the memory 902, the storage 903,the external connection interface 904, the camera 906, the sensor 907,the microphone 908, the input device 909, the display device 910, thespeaker 911, the wireless communication interface 912, and the auxiliarycontroller 919 with each other. The battery 918 supplies power to therespective blocks of the smartphone 900 depicted in FIG. 24 via a powersupply line partially indicated by a broken line in the figure. Forexample, the auxiliary controller 919 allows operations of minimumnecessary functions of the smartphone 900 in a sleep mode.

In the smartphone 900 depicted in FIG. 24 , one or more components ofthe upper layer processing unit 201 and the control unit 203 describedwith reference to FIG. 6 described with reference to FIG. 6 may bemounted on the wireless communication interface 912. Alternatively, atleast a part of these components may be mounted on the processor 901 orthe auxiliary controller 919. In an example, a module of a part (e.g.,BB processor 913) or all of the wireless communication interface 912,the processor 901, and/or the auxiliary controller 919 may be mounted onthe smartphone 900. The one or more components described above may bemounted on the module. In this case, the module may store a programunder which the processor functions as the one or more componentsdescribed above (i.e., program under which the processor executesoperations of the one or more components described above), and executethe program. In another example, a program under which the processorfunctions as the one or more components described above may be installedin the smartphone 900, and the wireless communication interface 912(e.g., BB processor 913), the processor 901, and/or the auxiliarycontroller 919 may execute the program. In this manner, the smartphone900 or the module may be provided as an apparatus including the one ormore components described above, or the program under which theprocessor functions as the one or more components described above may beprovided. In addition, a readable recording medium in which the programis recorded may be provided.

In addition, in the smartphone 900 depicted in FIG. 24 , the receptionunit 205 and the transmission unit 207 described with reference to FIG.6 may be mounted on the wireless communication interface 912 (e.g., RFcircuit 914), for example. Moreover, the transmission and receptionantenna 209 may be mounted on the antenna 916.

Second Application Example

FIG. 25 is a block diagram depicting an example of a schematicconfiguration of a car navigation apparatus 920 to which the technologyof the present disclosure is applicable. The car navigation apparatus920 includes a processor 921, a memory 922, a GPS (Global PositioningSystem) module 924, a sensor 925, a data interface 926, a content player927, a storage medium interface 928, an input device 929, a displaydevice 930, a speaker 931, a wireless communication interface 933, oneor more antenna switches 936, one or more antennas 937, and a battery938.

The processor 921 may be a CPU or a SoC, and controls a navigationfunction and other functions of the car navigation apparatus 920. Thememory 922 includes a RAM and a ROM, and stores programs executed by theprocessor 921 and data.

The GPS module 924 measures a position of the car navigation apparatus920 (e.g., latitude, longitude, and altitude) using a GPS signalreceived from a GPS satellite. For example, the sensor 925 may includesensors such as a gyro sensor, a geomagnetic sensor, and a pressuresensor. For example, the data interface 926 is connected to anin-vehicle network 941 via a not-shown terminal, and acquires datagenerated by a vehicle such as vehicle speed data.

The content player 927 reproduces content stored in a storage medium(e.g., CD or DVD) inserted into the storage medium interface 928. Forexample, the input device 929 includes a touch sensor for detecting atouch on a screen of the display device 930, buttons or switches, andothers, and receives an operation or an information input from a user.The display device 930 has a screen such as an LCD and an OLED display,and displays a navigation function or an image of content to bereproduced. The speaker 931 outputs the navigation function or voices ofconvent to be reproduced.

The wireless communication interface 933 supports any cellularcommunication method such as LTE and LTE-Advanced, and executes wirelesscommunication. The wireless communication interface 933 may typicallyinclude a BB processor 934, an RF circuit 935 and the like. For example,the BB processor 934 may perform encoding/decoding,modulation/demodulation, multiplexing/demultiplexing and the like, andexecutes various signal processes. On the other hand, the RF circuit 935may include a mixer, a filter, an amplifier and the like, and transmitsand receives wireless signals via the antenna 937. The wirelesscommunication interface 933 may be a one-chip module which integratesthe BB processor 934 and the RF circuit 935. As depicted in FIG. 25 ,the wireless communication interface 933 may include a plurality of theBB processors 934 and a plurality of the RF circuits 935. Note that,while FIG. 25 depicts the example of the wireless communicationinterface 933 which includes the plurality of BB processors 934 and theplurality of RF circuits 935, the wireless communication interface 933may include the single BB processor 934 and the single RF circuit 935.

In addition, the wireless communication interface 933 may support othertypes of wireless communication method such as a near fieldcommunication method, a proximity wireless communication method, and awireless LAN method as well as the cellular communication method. Inthis case, the wireless communication interface 933 may include the BBprocessor 934 and the RF circuit 935 for each of the wirelesscommunication methods.

Each of the antenna switches 936 switches a connection destination ofthe antenna 937 between a plurality of circuits included in the wirelesscommunication interface 933 (e.g., circuits for different wirelesscommunication methods).

Each of the antennas 937 includes a single or a plurality of antennaelements (e.g., a plurality of antenna elements constituting a MIMOantenna), and is used for transmission and reception of wireless signalsthrough the wireless communication interface 933. As depicted in FIG. 25, the car navigation apparatus 920 may include a plurality of theantennas 937. Note that, while FIG. 25 depicts an example of the carnavigation apparatus 920 which includes the plurality of antennas 937,the car navigation apparatus 920 may have the single antenna 937.

In addition, the car navigation apparatus 920 may include the antenna937 for each of the wireless communication methods. In this case, theantenna switch 936 may be eliminated from the configuration of the carnavigation apparatus 920.

The battery 938 supplies power to the respective blocks of the carnavigation apparatus 920 depicted in FIG. 25 via a power supply linepartially indicated by a broken line in the figure in addition, thebattery 938 accumulates power supplied from the vehicle.

In the car navigation apparatus 920 depicted in FIG. 25 , one or morecomponents of the upper layer processing unit 201 and the control unit203 described with reference to FIG. 6 described with reference to FIG.6 may be mounted on the wireless communication interface 933.Alternatively, at least a part of these components may be mounted on theprocessor 921. In an example, a module which includes a part (e.g., BBprocessor 934) or all of the wireless communication interface 933,and/or the processor 921 may be mounted on the car navigation apparatus920. The one or more components described above may be mounted on themodule. In this case, the module may store a program under which theprocessor functions as the one or more components described above (i.e.,program under which the processor executes operations of the one or morecomponents described above), and execute the program. In anotherexample, a program under which the processor functions as the one ormore components described above may be installed in the car navigationapparatus 920. The wireless communication interface 933 (e.g., BBprocessor 934), and/or the processor 921 may execute the program. Inthis manner, the car navigation apparatus 920 or the module may beprovided as an apparatus including the one or more components describedabove, or the program under which the processor functions as the one ormore components described above may be provided. In addition, a readablerecording medium in which the program is recorded may be provided.

In addition, in the car navigation apparatus 920 depicted in FIG. 25 ,for example, the reception unit 205 and the transmission unit 207described with reference to FIG. 6 may be mounted on the wirelesscommunication interface 933 (e.g., RF circuit 935). Moreover, thetransmission and reception antenna 209 may be mounted on the antenna937.

In addition, the technology according to the present disclosure may beimplemented as an in-vehicle system (or vehicle) 940 which includes oneor more blocks of the car navigation apparatus 920 described above, anin-vehicle network 941, and a vehicle-side module 942. In other words,the in-vehicle system (or vehicle) 940 may be provided as an apparatuswhich includes at least any one of the upper layer processing unit 201,the control unit 203, the reception unit 205, or the transmission unit207. The vehicle-side module 942 generates vehicle-side data such as avehicle speed, an engine rotation speed, and failure information, andoutputs the generated data to the in-vehicle network 941.

3. Conclusion

As described above, in the wireless communication system according tothe present embodiment, the base station apparatus performs control suchthat a plurality of reference signals associated with respective piecesof antenna information different from each other is transmitted to theterminal apparatus. In addition, the base station apparatus acquirescontrol information corresponding to at least any one of the pluralityof reference signals (e.g., information corresponding to the referencesignal selected by the terminal apparatus) from the terminal apparatusafter the random access response in the random access procedure istransmitted to the terminal apparatus. Moreover, the base stationapparatus controls following communication with the terminal apparatuson the basis of the antenna information corresponding to the acquiredcontrol information.

According to the wireless communication system of the present embodimentthus configured, the base station apparatus is capable of using aplurality of beams (e.g., best beam and one or more best beams next tothe best beam) during communication with the terminal apparatus afterthe random access response in the random access procedure in the pluralbeam operation. In this case, the base station apparatus is capable ofusing a plurality of beams in downlink transmission of the message 4 andfollowing messages in the random access procedure. Accordingly, in thewireless communication system of the present embodiment, robustness forpropagation losses produced by a shield or the like of wireless signalscan be secured more than in a case where only one beam is used,wherefore a procedure of an initial access can be completed more stablyand rapidly.

In addition, according to the wireless communication system of thepresent embodiment, the base station apparatus comes into a state wherea plurality of beams is usable for communication with the terminalapparatus before completion of the procedure of the initial access.Accordingly, the base station apparatus is capable of immediatelystarting communication using a plurality of beams without the necessityof performing a procedure to use a plurality of beams after completionof the procedure of the initial access.

In addition, according to the wireless communication system of thepresent embodiment as described above, correspondence (i.e., QCL)between various transmission signals and respective beams can beappropriately controlled in accordance with various conditions duringcommunication with the terminal apparatus using a plurality of beamsafter the random access response.

While the preferred embodiment according to the present disclosure hasbeen described above in detail with reference to the accompanyingdrawings, the technical range of the present disclosure is not limitedto this example. It is apparent that various modified examples orcorrection examples within a scope of the technical spirit described inthe claims may occur to those having ordinary knowledges in thetechnical field of the present disclosure. It is therefore understoodthat these examples obviously fall within the technical range of thepresent disclosure.

In addition, advantageous effects described in the present descriptionare presented only for explanation or as examples. Advantageous effectsto be produced therefore are not limited to these effects. Accordingly,the technology of the present disclosure may offer other advantageouseffects obvious to those skilled in the art in the light of thedescription of the present description in addition to or in place of theadvantageous effects described above.

Note that following configurations also fall within the technical rangeof the present disclosure.

(1)

A communication apparatus including:

-   -   a control unit that performs control such that a plurality of        reference signals associated with pieces of antenna information        different from each other is transmitted to a terminal        apparatus; and    -   an acquisition unit that acquires control information        corresponding to at least any one of the plurality of reference        signals from the terminal apparatus after a random access        response in a random access procedure is transmitted to the        terminal apparatus, in which the control unit controls following        communication with the terminal apparatus on the basis of the        antenna information corresponding to the acquired control        information.

(2)

The communication apparatus according to (1) described above, in which

-   -   the control unit controls setting of an antenna associated with        communication with the terminal apparatus on the basis of the        acquired control information after acquisition of the control        information in the random access procedure.

(3)

The communication apparatus according to (1) or (2) described above, inwhich

-   -   the acquisition unit acquires the control information        corresponding to two or more of the plurality of reference        signals from the terminal apparatus; and    -   the control unit determines two or more pieces of the antenna        information used for communication with the terminal apparatus        in accordance with the acquired control information.

(4)

The communication apparatus according to any one of (1) to (3) describedabove, in which

-   -   the control unit    -   determines first antenna information associated with        communication with the terminal apparatus before transmission of        the random access response to the terminal apparatus in the        random access procedure;    -   determines second antenna information associated with        communication with the terminal apparatus on the basis of the        acquired control information after transmission of the random        access response; and    -   controls communication with the terminal apparatus after        acquisition of the control information on the basis of at least        either the first antenna information or the second antenna        information.

(5)

The communication apparatus according to (4) described above, in which

-   -   the control unit    -   controls communication with the terminal apparatus on the basis        of the first antenna information before transmission of the        random access response; and    -   controls communication with the terminal apparatus on the basis        of the second antenna information after transmission of the        random access response.

(6)

The communication apparatus according to (4) described above, in which,

-   -   in communication with the terminal apparatus after acquisition        of the control information, the control unit    -   controls communication with the terminal apparatus on the basis        of the first antenna information in a case of initial        transmission of transmission data, and    -   controls communication with the terminal apparatus on the basis        of the second antenna information in a case of retransmission of        the transmission data.

(7)

The communication apparatus according to (4) described above, in which

-   -   the control unit    -   controls communication with the terminal apparatus on the basis        of the first antenna information in a case of transmission of a        signal via a physical channel belonging to a first search space,        and    -   controls communication with the terminal apparatus on the basis        of the second antenna information in a case of transmission of a        signal via a physical channel belonging to a second search space        different from the first search space.

(8)

The communication apparatus according to (4) described above, in which

-   -   the control unit    -   controls communication with the terminal apparatus on the basis        of the first antenna information in a case of transmission of a        signal using a first symbol, and    -   controls communication with the terminal apparatus on the basis        of the second antenna information in a case of transmission of a        signal using a second symbol different from the first symbol.

(9)

The communication apparatus according to any one of (1) to (8) describedabove, in which

-   -   the control unit performs control such that a plurality of        synchronization signal blocks as the plurality of reference        signals is transmitted to a terminal apparatus within a        communication range.

(10)

The communication apparatus according to any one of (1) to (8) describedabove, in which

-   -   the control unit    -   performs control such that a notice of information associated        with respective transmission conditions of the plurality of        reference signals is given to the terminal apparatus; and    -   performs control such that the plurality of reference signals is        transmitted to the terminal apparatus in accordance with the        transmission conditions.

(11)

The communication apparatus according to any one of (1) to (10)described above, in which

-   -   the control unit performs control such that directivity of a        transmission signal associated with communication with the        terminal apparatus becomes higher than directivity of the        reference signals.

(12)

The communication apparatus according to any one of (1) to (11)described above, in which

-   -   the antenna information includes information associated with        setting of at least any one of a channel, a path, an antenna, or        an antenna port.

(13)

A communication apparatus including:

-   -   a selection unit that selects at least a part of a plurality of        reference signals transmitted from a base station and associated        with pieces of antenna information different from each other,        the part of the plurality of reference signals being selected in        accordance with a reception result of the reference signals; and    -   a notice unit that gives a notice of control information        corresponding to the selected reference signal to the base        station after reception of a random access response transmitted        from the base station in a random access procedure.

(14)

The communication apparatus according to (13) described above, in which

-   -   the selection unit performs predetermined measurement for each        of the plurality of reference signals, and selects at least a        part of the reference signals in accordance with a result of the        measurement.

(15)

The communication apparatus according to (14) described above, in which

-   -   the selection unit measures at least either communication        quality or reception power of the reference signals for the        measurement.

(16)

The communication apparatus according to (14) or (15) described above,in which

-   -   the notice unit    -   gives a notice of control information corresponding to a first        reference signal selected from the plurality of reference        signals to the base station before reception of the random        access response, and    -   gives a notice of control information corresponding to a        difference of a result of the measurement between the first        reference signal and a second reference signal different from        the first reference signal and selected from the plurality of        reference signals to the base station after reception of the        random access response.

(17)

The communication apparatus according to any one of (13) to (16)described above, in which

-   -   the notice unit gives a notice of control information        corresponding to two or more selected reference signals to the        base station after reception of the random access response.

(18)

A communication method performed by a computer, the method including:

-   -   performing control such that a plurality of reference signals        associated with pieces of antenna information different from        each other is transmitted to a terminal apparatus, acquiring        control information corresponding to at least any one of the        plurality of reference signals from the terminal apparatus after        a random access response in a random access procedure is        transmitted to the terminal apparatus; and    -   controlling following communication with the terminal apparatus        on the basis of the antenna information corresponding to the        acquired control information.

(19)

A communication method performed by a computer, the method including:

-   -   selecting at least a part of a plurality of reference signals        transmitted from a base station and associated with pieces of        antenna information different from each other, the part of the        plurality of reference signals being selected in accordance with        a reception result of the reference signals; and    -   giving a notice of control information corresponding to the        selected reference signal to the base station after reception of        a random access response transmitted from the base station in a        random access procedure.

(20)

A program under which a computer executes:

-   -   performing control such that a plurality of reference signals        associated with pieces of antenna information different from        each other is transmitted to a terminal apparatus;    -   acquiring control information corresponding to at least any one        of the plurality of reference signals from the terminal        apparatus after a random access response in a random access        procedure is transmitted to the terminal apparatus; and    -   controlling following communication with the terminal apparatus        on the basis of the antenna information corresponding to the        acquired control information.

(21)

A program under which a computer executes:

-   -   selecting at least a part of a plurality of reference signals        transmitted from a base station and associated with pieces of        antenna information different from each other, the part of he        plurality of reference signals being selected in accordance with        a reception result of the reference signals; and    -   giving a notice of control information corresponding to the        selected reference signal to the base station after reception of        a random access response transmitted from the base station in a        random access procedure.

REFERENCE SIGNS LIST

-   -   1 Base station apparatus    -   101 Upper layer processing unit    -   103 Control unit    -   105 Reception unit    -   1051 Decoding unit    -   1053 Demodulation unit    -   1055 Demultiplexing unit    -   1057 Wireless reception unit    -   1059 Channel measurement unit    -   107 Transmission unit    -   1071 Encoding unit    -   1073 Modulation unit    -   1075 Multiplexing unit    -   1077 Wireless transmission unit    -   1079 Link reference signal generation unit    -   109 Transmission and reception antenna    -   130 Network communication unit    -   2 Terminal apparatus    -   201 Upper layer processing unit    -   203 Control unit    -   205 Reception unit    -   2051 Decoding unit    -   2053 Demodulation unit    -   2055 Demultiplexing unit    -   2057 Wireless reception unit    -   2059 Channel measurement unit    -   207 Transmission unit    -   2071 Encoding unit    -   2073 Modulation unit    -   2075 Multiplexing unit    -   2077 Wireless transmission unit    -   2079 Link reference signal generation unit    -   209 Transmission and reception antenna

What is claimed is:
 1. A base station device, comprising: a radiotransceiver; and circuitry configured to control the radio transceiverto: transmit one or more synchronization signal blocks, each of the oneor more synchronization signal blocks comprising: a New Radio (NR)Primary Synchronization Signal (PSS), an NR Secondary SynchronizationSignal (SSS), and an NR Physical Broadcast Channel (PBCH), wherein theNR PBCH carries an NR Master Information Block (MIB) which comprisescommon control resource set information where an NR Physical DownlinkControl Channel (PDCCH) is located; transmit the NR PDCCH to whichCyclic Redundancy Check (CRC) scrambled with a System Information RadioNetwork Temporary Identifier (SI-RNTI) is added; transmit an NR PhysicalDownlink Shared Channel (PDSCH) scheduled by the NR PDCCH; receive aPRACH associated with a first synchronization signal block selected fromamong the one or more synchronization signal blocks based on ReferenceSignal Received Power (RSRP) measurement by a user equipment; transmit aRandom Access Response (RAR) corresponding to the received PRACH; andreceive, after the transmission of the RAR to the user equipment,information regarding a second beam which comprises: one or moresynchronization signal block indices, or information corresponding toone or more Channel State Information-Reference Signals (CSI-RSs),wherein a Demodulation Reference Signal (DMRS) of the NR PDCCH, a DMRSof the NR PDSCH and the first synchronization signal block, before thetransmission of the RAR to the user equipment, are Quasi-Co-Location(QCL).
 2. The base station device according to claim 1, wherein the DMRSof the NR PDCCH, the DMRS of the NR PDSCH and the first synchronizationsignal block, before the transmission of the RAR to the user equipment,are QCL with respect to: delay spread, Doppler spread, Doppler shift,average gain and average delay.
 3. The base station device according toclaim 2, wherein the circuitry is configured to control the radiotransceiver to: transmit CSI-RS configuration information; and transmitthe one or more CSI-RSs based on the CSI-RS configuration information,wherein the CSI-RS configuration information comprises: informationindicating which a synchronization signal block is QCL, and informationindicating which the DMRS of PDCCH is QCL.
 4. The base station deviceaccording to claim 3, wherein a common search space for the commoncontrol resource set where the NR PDCCH is located is based on asynchronization signal block index of the first synchronization signalblock.
 5. A user equipment, comprising: a radio transceiver; andcircuitry configured to control the radio transceiver to: receive one ormore synchronization signal blocks, each of the one or moresynchronization signal blocks comprising: a New Radio (NR) PrimarySynchronization Signal (PSS), an NR Secondary Synchronization Signal(SSS), and an NR Physical Broadcast Channel (PBCH), wherein the NR PBCHcarries NR Master Information Block (MIB) which comprises common controlresource set information where an NR Physical Downlink Control Channel(PDCCH) is located; receive the NR PDCCH to which Cyclic RedundancyCheck (CRC) scrambled with a System Information Radio Network TemporaryIdentifier (SI-RNTI) is added; receive an NR Physical Downlink SharedChannel (PDSCH) scheduled by the NR PDCCH; transmit a PRACH associatedwith a first synchronization signal block selected from among the one ormore synchronization signal blocks based on Reference Signal ReceivedPower (RSRP) measurement by the user equipment; receive a Random AccessResponse (RAR) corresponding to the transmitted PRACH; and transmit,after the reception of the RAR from a base station, informationregarding a second beam which comprises: one or more synchronizationsignal block indices, or information corresponding to one or moreChannel State Information-Reference Signals (CSI-RSs), wherein aDemodulation Reference Signal (DMRS) of the NR PDCCH, a DMRS of the NRPDSCH and the first synchronization signal block, before the receptionof the RAR from the base station, are Quasi-Co-Location (QCL).
 6. Theuser equipment according to claim 5, wherein the DMRS of the NR PDCCH,the DMRS of the NR PDSCH and the first synchronization signal block,before transmitting the RAR to the user equipment, are QCL with respectto: delay spread, Doppler spread, Doppler shift, average gain andaverage delay.
 7. The user equipment according to claim 6, wherein thecircuitry is configured to control the radio transceiver to: receiveCSI-RS configuration information; and receive the one or more CSI-RSsbased on the CSI-RS configuration information, wherein the CSI-RSconfiguration information comprises: information indicating which asynchronization signal block is QCL, and information indicating whichthe DMRS of PDCCH is QCL.
 8. The user equipment according to claim 6,wherein a common search space for the common control resource set wherethe NR PDCCH is located is based on a synchronization signal block indexof the first synchronization signal block.
 9. A electronic device,comprising: circuitry configured to control a radio transceiver to:receive one or more synchronization signal blocks, each of the one ormore synchronization signal blocks comprising: a New Radio (NR) PrimarySynchronization Signal (PSS), an NR Secondary Synchronization Signal(SSS), and an NR Physical Broadcast Channel (PBCH), wherein the NR PBCHcarries an NR Master Information Block (MIB) which comprises commoncontrol resource set information where an NR Physical Downlink ControlChannel (PDCCH) is located; receive the NR PDCCH to which CyclicRedundancy Check (CRC) scrambled with a System Information Radio NetworkTemporary Identifier (SI-RNTI) is added; receive an NR Physical DownlinkShared Channel (PDSCH) scheduled by the NR PDCCH; transmit a PRACHassociated with a first synchronization signal block selected from amongthe one or more synchronization signal blocks based on Reference SignalReceived Power (RSRP) measurement; receive a Random Access Response(RAR) corresponding to the transmitted PRACH; and transmit, afterreceiving the RAR from a base station, information regarding a secondbeam which comprises: one or more synchronization signal block indices,or information corresponding to one or more Channel StateInformation-Reference Signals (CSI-RSs), wherein a DemodulationReference Signal (DMRS) of the NR PDCCH, a DMRS of the NR PDSCH and thefirst synchronization signal block, before the reception of the RAR fromthe base station, are Quasi-Co-Location (QCL).
 10. The electronic deviceaccording to claim 9, wherein the DMRS of the NR PDCCH, the DMRS of theNR PDSCH and the first synchronization signal block, before transmittingthe RAR to the electronic device, are QCL with respect to: delay spread,Doppler spread, Doppler shift, average gain and average delay.
 11. Theelectronic device according to claim 10, wherein the circuitry isconfigured to control the radio transceiver to: receive CSI-RSconfiguration information; and receive the one or more CSI-RSs based onthe CSI-RS configuration information, wherein the CSI-RS configurationinformation comprises: information indicating which a synchronizationsignal block is QCL, and information indicating which the DMRS of PDCCHis QCL.
 12. The electronic device according to claim 10, wherein acommon search space for the common control resource set where the NRPDCCH is located is based on a synchronization signal block index of thefirst synchronization signal block.
 13. A method for a base station, themethod comprising: transmitting one or more synchronization signalblocks, each of the one or more synchronization signal blockscomprising: a New Radio (NR) Primary Synchronization Signal (PSS), an NRSecondary Synchronization Signal (SSS), and an NR Physical BroadcastChannel (PBCH), wherein the NR PBCH carries an NR Master InformationBlock (MIB) which comprises common control resource set informationwhere an NR Physical Downlink Control Channel (PDCCH) is located;transmitting the NR PDCCH to which Cyclic Redundancy Check (CRC)scrambled with a System Information Radio Network Temporary Identifier(SI-RNTI) is added; transmitting an NR Physical Downlink Shared Channel(PDSCH) scheduled by the NR PDCCH; receiving a PRACH associated with afirst synchronization signal block selected from among the one or moresynchronization signal blocks based on Reference Signal Received Power(RSRP) measurement by a user equipment; transmitting a Random AccessResponse (RAR) corresponding to the received PRACH; and receiving, aftertransmitting the RAR to the user equipment, information regarding asecond beam which comprises: one or more synchronization signal blockindices, or information corresponding to one or more Channel StateInformation-Reference Signals (CSI-RSs), wherein a DemodulationReference Signal (DMRS) of the NR PDCCH, a DMRS of the NR PDSCH and thefirst synchronization signal block, before transmitting the RAR to theuser equipment, are Quasi-Co-Location (QCL).
 14. A method for a userequipment, the method comprising: receiving one or more synchronizationsignal blocks, each of the one or more synchronization signal blockscomprising: a New Radio (NR) Primary Synchronization Signal (PSS), an NRSecondary Synchronization Signal (SSS), and an NR Physical BroadcastChannel (PBCH), wherein the NR PBCH carries NR Master Information Block(MIB) which comprises common control resource set information where anNR Physical Downlink Control Channel (PDCCH) is located; receiving theNR PDCCH to which Cyclic Redundancy Check (CRC) scrambled with a SystemInformation Radio Network Temporary Identifier (SI-RNTI) is added;receiving an NR Physical Downlink Shared Channel (PDSCH) scheduled bythe NR PDCCH; transmitting a PRACH associated with a firstsynchronization signal block selected from among the one or moresynchronization signal blocks based on Reference Signal Received Power(RSRP) measurement by the user equipment; receiving a Random AccessResponse (RAR) corresponding to the transmitted PRACH; and transmitting,after receiving the RAR from a base station, information regarding asecond beam which comprises: one or more synchronization signal blockindices, or information corresponding to one or more Channel StateInformation-Reference Signals (CSI-RSs), wherein a DemodulationReference Signal (DMRS) of the NR PDCCH, a DMRS of the NR PDSCH and thefirst synchronization signal block, before receiving the RAR from thebase station, are Quasi-Co-Location (QCL).